diff --git a/src/tray/windows-tray.ps1 b/src/tray/windows-tray.ps1
index f005c6ea931..3112ee6fdc9 100644
--- a/src/tray/windows-tray.ps1
+++ b/src/tray/windows-tray.ps1
@@ -1,4 +1,4 @@
-param(
+param(
   [Parameter(Mandatory = $true)][string]$BunPath,
   [Parameter(Mandatory = $true)][string]$CliPath,
   [Parameter(Mandatory = $true)][string]$CodexHome,
@@ -15,6 +15,19 @@ Add-Type -AssemblyName System.Windows.Forms
 Add-Type -AssemblyName System.Drawing
 try { [System.Windows.Forms.Application]::EnableVisualStyles() } catch { $null = $_ }
 
+# Chinese UI cultures get Chinese tray text; every other locale keeps the English strings. The
+# judgment is a named function so it can be exercised directly instead of only through a live
+# desktop, where a selector that always answered English would still look correct.
+function Test-TrayChineseCulture([string]$CultureName) {
+  return $CultureName -like "zh*"
+}
+$script:isZh = Test-TrayChineseCulture ([System.Globalization.CultureInfo]::CurrentUICulture.Name)
+function Get-TrayText {
+  param([string]$En, [string]$Zh)
+  if ($script:isZh) { return $Zh }
+  return $En
+}
+
 # Normalize aliases before deriving singleton/event names. Without this,
 # C:\path and C:\path\. create separate tray instances for the same home.
 function Normalize-HomePath([string]$Value) {
@@ -127,7 +140,7 @@ function Start-OcxCommand([string[]]$CommandArgs, [switch]$TrackExit) {
     return $true
   } catch {
     Write-ActionLog "launch failed: $($_.Exception.GetType().Name)"
-    $notify.ShowBalloonTip(5000, "opencodex action failed", "The action could not start. Open the logs folder or run ocx doctor.", [System.Windows.Forms.ToolTipIcon]::Error)
+    $notify.ShowBalloonTip(5000, (Get-TrayText "opencodex action failed" "opencodex 操作失败"), (Get-TrayText "The action could not start. Open the logs folder or run ocx doctor." "操作无法启动。打开日志文件夹或运行 ocx doctor。"), [System.Windows.Forms.ToolTipIcon]::Error)
     return $false
   }
 }
@@ -396,19 +409,19 @@ $statusItem = New-Object System.Windows.Forms.ToolStripMenuItem
 $statusItem.Enabled = $false
 $safetyItem = New-Object System.Windows.Forms.ToolStripMenuItem
 $safetyItem.Enabled = $false
-$openItem = $menu.Items.Add("Open Dashboard")
-$updateItem = $menu.Items.Add("Update available")
+$openItem = $menu.Items.Add((Get-TrayText "Open Dashboard" "打开面板"))
+$updateItem = $menu.Items.Add((Get-TrayText "Update available" "有可用更新"))
 $updateItem.Visible = $false
 $updateItem.Enabled = $false
-$startItem = $menu.Items.Add("Start Proxy")
-$stopItem = $menu.Items.Add("Stop Proxy and Restore Native Routing")
-$restartItem = $menu.Items.Add("Restart Proxy")
+$startItem = $menu.Items.Add((Get-TrayText "Start Proxy" "启动代理"))
+$stopItem = $menu.Items.Add((Get-TrayText "Stop Proxy and Restore Native Routing" "停止代理并还原原生路由"))
+$restartItem = $menu.Items.Add((Get-TrayText "Restart Proxy" "重启代理"))
 [void]$menu.Items.Add((New-Object System.Windows.Forms.ToolStripSeparator))
 [void]$menu.Items.Add($statusItem)
 [void]$menu.Items.Add($safetyItem)
-$logsItem = $menu.Items.Add("Open Logs Folder")
+$logsItem = $menu.Items.Add((Get-TrayText "Open Logs Folder" "打开日志文件夹"))
 [void]$menu.Items.Add((New-Object System.Windows.Forms.ToolStripSeparator))
-$exitItem = $menu.Items.Add("Exit Tray")
+$exitItem = $menu.Items.Add((Get-TrayText "Exit Tray" "退出托盘"))
 
 $script:online = $false
 $script:port = 10100
@@ -463,6 +476,14 @@ function Set-PendingAction([string]$Action, [int]$TimeoutSeconds) {
 function Complete-PendingAction([bool]$Success) {
   if ($null -eq $script:pendingAction) { return }
   $action = $script:pendingAction
+  # The pending value stays English because it is compared against the labels the click
+  # handlers set; only the text a user reads is localized.
+  $displayAction = switch ($action) {
+    "Start Proxy" { Get-TrayText "Start Proxy" "启动代理" }
+    "Stop Proxy" { Get-TrayText "Stop Proxy" "停止代理" }
+    "Restart Proxy" { Get-TrayText "Restart Proxy" "重启代理" }
+    default { $action }
+  }
   $script:pendingAction = $null
   if ($null -ne $script:pendingProcess) {
     try {
@@ -474,10 +495,10 @@ function Complete-PendingAction([bool]$Success) {
   }
   if ($Success) {
     Write-ActionLog "$action completed (port=$($script:port), pid=$($script:proxyPid))"
-    $notify.ShowBalloonTip(2500, "opencodex", "$action completed.", [System.Windows.Forms.ToolTipIcon]::Info)
+    $notify.ShowBalloonTip(2500, "opencodex", (Get-TrayText "$displayAction completed." "$displayAction 已完成。"), [System.Windows.Forms.ToolTipIcon]::Info)
   } else {
     Write-ActionLog "$action failed to reach the expected state"
-    $notify.ShowBalloonTip(5000, "opencodex action failed", "$action did not reach the expected state. Open the logs folder or run ocx doctor.", [System.Windows.Forms.ToolTipIcon]::Error)
+    $notify.ShowBalloonTip(5000, (Get-TrayText "opencodex action failed" "opencodex 操作失败"), (Get-TrayText "$displayAction did not reach the expected state. Open the logs folder or run ocx doctor." "$displayAction 未达到预期状态。打开日志文件夹或运行 ocx doctor。"), [System.Windows.Forms.ToolTipIcon]::Error)
   }
 }
 
@@ -536,8 +557,8 @@ function Update-TrayState {
     Start-StartupHealthProbe
   }
   if ($script:online) {
-    $statusItem.Text = "Proxy: Online (port $($script:port))"
-    $notify.Text = "opencodex: Online"
+    $statusItem.Text = (Get-TrayText "Proxy: Online (port $($script:port))" "代理: 在线 (端口 $($script:port))")
+    $notify.Text = (Get-TrayText "opencodex: Online" "opencodex: 在线")
     $startItem.Enabled = $false
     $stopItem.Enabled = $true
     $restartItem.Enabled = $true
@@ -547,21 +568,27 @@ function Update-TrayState {
     # diagnostic is cleaned up outside the online-only UI branch.
     $startup = $script:startupHealth
     if ($null -ne $startup) {
-      $label = if ($startup.status -eq "at-risk") { "At risk" } elseif ($startup.status -eq "protected") { "Protected" } else { "Native routing" }
-      $safetyItem.Text = "Restart safety: $label"
+      $label = if ($startup.status -eq "at-risk") {
+        Get-TrayText "At risk" "有风险"
+      } elseif ($startup.status -eq "protected") {
+        Get-TrayText "Protected" "已保护"
+      } else {
+        Get-TrayText "Native routing" "原生路由"
+      }
+      $safetyItem.Text = (Get-TrayText "Restart safety: $label" "重启保护: $label")
       $notify.Icon = if ($startup.status -eq "at-risk") {
         if ($script:updateAvailable) { $warningUpdateIcon } else { $warningIcon }
       } else {
         if ($script:updateAvailable) { $onlineUpdateIcon } else { $onlineIcon }
       }
     } else {
-      $safetyItem.Text = "Restart safety: unavailable"
+      $safetyItem.Text = (Get-TrayText "Restart safety: unavailable" "重启保护: 不可用")
       $notify.Icon = if ($script:updateAvailable) { $warningUpdateIcon } else { $warningIcon }
     }
   } else {
-    $statusItem.Text = "Proxy: Offline"
-    $safetyItem.Text = "Restart safety: start the proxy to inspect"
-    $notify.Text = "opencodex: Offline"
+    $statusItem.Text = (Get-TrayText "Proxy: Offline" "代理: 离线")
+    $safetyItem.Text = (Get-TrayText "Restart safety: start the proxy to inspect" "重启保护: 启动代理后查看")
+    $notify.Text = (Get-TrayText "opencodex: Offline" "opencodex: 离线")
     $notify.Icon = if ($script:updateAvailable) { $offlineUpdateIcon } else { $offlineIcon }
     $startItem.Enabled = $true
     $stopItem.Enabled = $false
@@ -607,7 +634,7 @@ $openItem.add_Click({ Start-OcxCommand @("gui") })
 $updateItem.add_Click({ Start-OcxCommand @("gui") })
 $startItem.add_Click({
   if (-not (Set-PendingAction "Start Proxy" 75)) { return }
-  $statusItem.Text = "Proxy: Starting..."
+  $statusItem.Text = (Get-TrayText "Proxy: Starting..." "代理: 启动中...")
   # service start can spend 20s and the CLI then observes health for another 40s.
   $startProcess = Start-OcxCommand @("__tray-start") -TrackExit
   if ($startProcess -is [System.Diagnostics.Process]) {
@@ -618,7 +645,7 @@ $startItem.add_Click({
 })
 $stopItem.add_Click({
   if (-not (Set-PendingAction "Stop Proxy" 15)) { return }
-  $statusItem.Text = "Proxy: Stopping..."
+  $statusItem.Text = (Get-TrayText "Proxy: Stopping..." "代理: 停止中...")
   $stopProcess = Start-OcxCommand @("stop") -TrackExit
   if ($stopProcess -is [System.Diagnostics.Process]) {
     $script:pendingProcess = $stopProcess
@@ -628,7 +655,7 @@ $stopItem.add_Click({
 })
 $restartItem.add_Click({
   if (-not (Set-PendingAction "Restart Proxy" 160)) { return }
-  $statusItem.Text = "Proxy: Restarting..."
+  $statusItem.Text = (Get-TrayText "Proxy: Restarting..." "代理: 重启中...")
   # /api/system/restart may drain active work for 60s and then spend up to 70s
   # handing off to an identity-verified replacement. The tray observes health/PID
   # rather than the detached CLI exit, so keep a watchdog margin around that shared
@@ -665,7 +692,7 @@ $timer.add_Tick({
 $notify.ContextMenuStrip = $menu
 $notify.Icon = $offlineIcon
 $notify.Visible = $true
-$notify.Text = "opencodex: Checking..."
+$notify.Text = (Get-TrayText "opencodex: Checking..." "opencodex: 检查中...")
 
 try {
   Initialize-UpdateBadgeReader
diff --git a/tests/helpers/windows-tray-i18n-driver.ps1 b/tests/helpers/windows-tray-i18n-driver.ps1
new file mode 100644
index 00000000000..2c84bbe2c27
--- /dev/null
+++ b/tests/helpers/windows-tray-i18n-driver.ps1
@@ -0,0 +1,98 @@
+# Behavioral driver for the tray's locale selection.
+#
+# Loads the REAL Test-TrayChineseCulture / Get-TrayText / Complete-PendingAction out of
+# src/tray/windows-tray.ps1 via the PowerShell AST (function definitions only - the top-level tray
+# UI never runs) and reports what each culture actually renders and notifies. A selector or a
+# notification that always answered English would pass a source-text check and fail here.
+param(
+  [Parameter(Mandatory = $true)][string]$TrayScriptPath,
+  [Parameter(Mandatory = $true)][string]$ResultPath
+)
+$ErrorActionPreference = "Stop"
+
+# Complete-PendingAction names ToolTipIcon in its balloon call. The tray script loads WinForms at
+# its top level, which this driver never runs, so load it here for the enum to resolve.
+Add-Type -AssemblyName System.Windows.Forms
+
+$tokens = $null
+$parseErrors = $null
+$ast = [System.Management.Automation.Language.Parser]::ParseFile($TrayScriptPath, [ref]$tokens, [ref]$parseErrors)
+if ($parseErrors.Count -gt 0) { throw "tray script parse failed: $($parseErrors[0].Message)" }
+$wanted = @(
+  "Test-TrayChineseCulture",
+  "Get-TrayText",
+  "Complete-PendingAction"
+)
+$definitions = $ast.FindAll({ param($node) $node -is [System.Management.Automation.Language.FunctionDefinitionAst] }, $true)
+$loaded = @()
+foreach ($fn in $definitions) {
+  if ($wanted -contains $fn.Name) {
+    # Dot-source the full definition extent so each function is defined exactly as the tray
+    # script declares it, params included.
+    . ([ScriptBlock]::Create($fn.Extent.Text))
+    $loaded += $fn.Name
+  }
+}
+$missing = @($wanted | Where-Object { $loaded -notcontains $_ })
+if ($missing.Count -gt 0) { throw "tray script is missing functions: $($missing -join ', ')" }
+
+# The action log is a file append the driver has no use for; the notification is what it asserts.
+function Write-ActionLog([string]$Message) { }
+
+$cultureDecisions = [ordered]@{}
+foreach ($name in @("zh-CN", "zh-TW", "zh-Hans", "en-US", "ja-JP", "")) {
+  $cultureDecisions[$name] = [bool](Test-TrayChineseCulture $name)
+}
+
+$rendered = [ordered]@{}
+foreach ($isZh in @($false, $true)) {
+  $script:isZh = $isZh
+  $rendered[$(if ($isZh) { "zh" } else { "en" })] = [ordered]@{
+    open = Get-TrayText "Open Dashboard" "打开面板"
+    start = Get-TrayText "Start Proxy" "启动代理"
+    restart = Get-TrayText "Restart Proxy" "重启代理"
+    exit = Get-TrayText "Exit Tray" "退出托盘"
+    status = Get-TrayText "opencodex: Online" "opencodex: 在线"
+  }
+}
+
+# Capture what Complete-PendingAction actually shows. The WinForms NotifyIcon is replaced by a
+# stub that records each balloon tip, so both completion branches are asserted as rendered text
+# rather than as script source.
+$global:trayNotifications = New-Object System.Collections.ArrayList
+$notify = New-Object PSObject
+$notify | Add-Member -MemberType ScriptMethod -Name ShowBalloonTip -Value {
+  param($timeout, $title, $text, $icon)
+  [void]$global:trayNotifications.Add([ordered]@{ title = $title; text = $text })
+}
+
+$notifications = [ordered]@{}
+foreach ($isZh in @($false, $true)) {
+  $script:isZh = $isZh
+  $script:port = 10100
+  $script:proxyPid = 4242
+  $script:pendingProcess = $null
+  $perAction = [ordered]@{}
+  foreach ($action in @("Start Proxy", "Stop Proxy", "Restart Proxy")) {
+    $branch = [ordered]@{}
+    foreach ($success in @($true, $false)) {
+      $global:trayNotifications.Clear()
+      $script:pendingAction = $action
+      Complete-PendingAction $success
+      $tip = $global:trayNotifications[0]
+      $branch[$(if ($success) { "ok" } else { "fail" })] = [ordered]@{
+        title = $tip.title
+        text = $tip.text
+      }
+    }
+    $perAction[$action] = $branch
+  }
+  $notifications[$(if ($isZh) { "zh" } else { "en" })] = $perAction
+}
+
+$result = [ordered]@{
+  cultureDecisions = $cultureDecisions
+  rendered = $rendered
+  notifications = $notifications
+}
+[System.IO.File]::WriteAllText($ResultPath, ($result | ConvertTo-Json -Depth 8 -Compress), (New-Object System.Text.UTF8Encoding($false)))
diff --git a/tests/helpers/windows-tray-probe-lifecycle-driver.ps1 b/tests/helpers/windows-tray-probe-lifecycle-driver.ps1
index 15adf55ac1f..00ea31af25e 100644
--- a/tests/helpers/windows-tray-probe-lifecycle-driver.ps1
+++ b/tests/helpers/windows-tray-probe-lifecycle-driver.ps1
@@ -36,6 +36,7 @@ $ast = [System.Management.Automation.Language.Parser]::ParseFile($TrayScriptPath
 if ($parseErrors.Count -gt 0) { throw "tray script parse failed: $($parseErrors[0].Message)" }
 $wanted = @(
   "Write-ActionLog",
+  "Get-TrayText",
   "Normalize-HomePath",
   "ConvertTo-NativeArgument",
   "Set-OcxChildEnvironment",
diff --git a/tests/windows/windows-tray.test.ts b/tests/windows/windows-tray.test.ts
index 44debc13a3f..e49581b8257 100644
--- a/tests/windows/windows-tray.test.ts
+++ b/tests/windows/windows-tray.test.ts
@@ -884,5 +884,85 @@ describe("Windows tray packaging and command safety", () => {
     const asUtf8 = Buffer.from(cp1252).toString("utf8");
     expect(parseWindowsTrayRunValue(asUtf8, runValue)).not.toBe(command);
   });
+
+  // Behavioral proof for the locale selection: the driver loads the REAL
+  // Test-TrayChineseCulture / Get-TrayText / Complete-PendingAction out of windows-tray.ps1 (via
+  // the PowerShell AST, so comment and whitespace edits cannot fake it) and reports what each
+  // culture actually renders and notifies. A selector, or a notification that kept using the
+  // English pending value, would pass a source-text check and fail here.
+  test("tray text and completion notifications follow the UI culture", () => {
+    if (process.platform !== "win32") return;
+    const root = mkdtempSync(join(tmpdir(), "ocx-tray-i18n-"));
+    try {
+      const resultPath = join(root, "result.json");
+      const run = Bun.spawnSync([
+        windowsPowerShellPath(), "-NoProfile", "-NonInteractive", "-ExecutionPolicy", "Bypass",
+        "-File", helperPath("windows-tray-i18n-driver.ps1"),
+        "-TrayScriptPath", repoPath("src", "tray", "windows-tray.ps1"),
+        "-ResultPath", resultPath,
+      ], { stdout: "pipe", stderr: "pipe" });
+      expect(run.exitCode, run.stderr.toString()).toBe(0);
+      const result = JSON.parse(readFileSync(resultPath, "utf8")) as {
+        cultureDecisions: Record<string, boolean>;
+        rendered: Record<string, Record<string, string>>;
+        notifications: Record<string, Record<string, {
+          ok: { title: string; text: string };
+          fail: { title: string; text: string };
+        }>>;
+      };
+      expect(result.cultureDecisions).toEqual({
+        "zh-CN": true, "zh-TW": true, "zh-Hans": true, "en-US": false, "ja-JP": false, "": false,
+      });
+      expect(result.rendered.zh).toEqual({
+        open: "打开面板",
+        start: "启动代理",
+        restart: "重启代理",
+        exit: "退出托盘",
+        status: "opencodex: 在线",
+      });
+      expect(result.rendered.en).toEqual({
+        open: "Open Dashboard",
+        start: "Start Proxy",
+        restart: "Restart Proxy",
+        exit: "Exit Tray",
+        status: "opencodex: Online",
+      });
+
+      // The pending value stays English for state comparisons; the notification a user reads must
+      // not carry it, on either branch.
+      // The pending value stays English for state comparisons; the notification a user reads must
+      // not carry it, on either branch and for every action the tray can run.
+      const expected = {
+        zh: {
+          "Start Proxy": { ok: "启动代理 已完成。", fail: "启动代理 未达到预期状态。打开日志文件夹或运行 ocx doctor。" },
+          "Stop Proxy": { ok: "停止代理 已完成。", fail: "停止代理 未达到预期状态。打开日志文件夹或运行 ocx doctor。" },
+          "Restart Proxy": { ok: "重启代理 已完成。", fail: "重启代理 未达到预期状态。打开日志文件夹或运行 ocx doctor。" },
+        },
+        en: {
+          "Start Proxy": { ok: "Start Proxy completed.", fail: "Start Proxy did not reach the expected state. Open the logs folder or run ocx doctor." },
+          "Stop Proxy": { ok: "Stop Proxy completed.", fail: "Stop Proxy did not reach the expected state. Open the logs folder or run ocx doctor." },
+          "Restart Proxy": { ok: "Restart Proxy completed.", fail: "Restart Proxy did not reach the expected state. Open the logs folder or run ocx doctor." },
+        },
+      };
+      for (const locale of ["zh", "en"] as const) {
+        expect(Object.keys(result.notifications[locale])).toEqual(["Start Proxy", "Stop Proxy", "Restart Proxy"]);
+        for (const [action, want] of Object.entries(expected[locale])) {
+          expect(result.notifications[locale][action]).toEqual({
+            ok: { title: "opencodex", text: want.ok },
+            fail: {
+              title: locale === "zh" ? "opencodex 操作失败" : "opencodex action failed",
+              text: want.fail,
+            },
+          });
+          if (locale === "zh") {
+            expect(result.notifications.zh[action].ok.text).not.toContain(action);
+            expect(result.notifications.zh[action].fail.text).not.toContain(action);
+          }
+        }
+      }
+    } finally {
+      removeTreeWithRetry(root);
+    }
+  });
 });
 import { ManagementRequest as Request } from "../helpers/management-auth";