diff --git a/deploy.ps1 b/deploy.ps1
index 9d222ff..ef6dadb 100644
--- a/deploy.ps1
+++ b/deploy.ps1
@@ -1,14 +1,20 @@
-# GERP frontend deploy script: build and sync dist to production dir (TempLate/GERP)
+# GERP frontend deploy script: zero-downtime build and sync to production dir (TempLate/GERP)
 #
 # IMPORTANT: keep this file pure ASCII. PS 5.1 parses BOM-less UTF-8 files
 # using the ANSI codepage, so non-ASCII text would be garbled.
 #
-# Usage:
-#   1. Clean old artifacts (dist and TempLate/GERP/assets) so no stale hashes remain
-#   2. Full rebuild (vue-tsc type check + vite build)
-#   3. Sync dist to TempLate/GERP (index.html + assets)
-#   4. Verify TempLate matches dist exactly
+# Order matters (zero downtime):
+#   1. Build first (dist/) -- prod keeps serving the old build meanwhile
+#   2. Copy new assets/dirs (additive) -- old index.html still points to old
+#      assets, which are still present, so no request can 404
+#   3. Swap index.html last -- every asset it references already exists
+#   4. Prune stale files in the mirror dirs (assets / tinymce)
+#   5. Verify prod matches dist
 #
+# Never delete index.html / assets before the new build is ready: SubdomainView
+# (gvsds/apps/core/views.py) serves gerp.gvsds.com straight out of this directory.
+#
+# Usage:
 #   Run:  .\deploy.ps1
 #   (if execution policy blocks:  Set-ExecutionPolicy -Scope Process Bypass)
 
@@ -23,32 +29,10 @@ $IndexHtml     = Join-Path $ProdRoot 'index.html'
 Write-Host "`n===== GERP DEPLOY START =====" -ForegroundColor Cyan
 Write-Host "Project dir : $ProjectRoot"
 Write-Host "Prod dir    : $ProdRoot"
-Write-Host ""
-
-# 1. Clean old artifacts
-Write-Host '[1/4] Cleaning old build artifacts...' -ForegroundColor Yellow
-if (Test-Path $DistDir) {
-    Remove-Item -Recurse -Force $DistDir
-    Write-Host "  removed: $DistDir"
-}
-if (Test-Path $ProdAssetsDir) {
-    Remove-Item -Recurse -Force $ProdAssetsDir
-    Write-Host "  removed: $ProdAssetsDir"
-}
-if (Test-Path $IndexHtml) {
-    Remove-Item -Force $IndexHtml
-    Write-Host "  removed: $IndexHtml"
-}
-# tinymce 为构建产物（裁剪后的运行时文件），清理防旧完整包残留
-$ProdTinymceDir = Join-Path $ProdRoot 'tinymce'
-if (Test-Path $ProdTinymceDir) {
-    Remove-Item -Recurse -Force $ProdTinymceDir
-    Write-Host "  removed: $ProdTinymceDir"
-}
 Write-Host ''
 
-# 2. Full build (vue-tsc type check + vite build)
-Write-Host '[2/4] Running npm run build (type check + full build)...' -ForegroundColor Yellow
+# 1. Full build (vue-tsc type check + vite build). Non-destructive for prod.
+Write-Host '[1/5] Running npm run build (type check + full build)...' -ForegroundColor Yellow
 Push-Location $ProjectRoot
 try {
     npm run build
@@ -61,26 +45,67 @@ try {
 Write-Host '  Build OK'
 Write-Host ''
 
-# 3. Sync artifacts to prod dir
-Write-Host '[3/4] Syncing artifacts to prod dir...' -ForegroundColor Yellow
 if (-not (Test-Path $ProdRoot)) {
     New-Item -ItemType Directory -Path $ProdRoot -Force | Out-Null
 }
-Copy-Item -Recurse -Force (Join-Path $DistDir '*') $ProdRoot
-Copy-Item -Force (Join-Path $DistDir 'index.html') $IndexHtml
-Write-Host '  Sync done'
+
+# 2. Copy new assets/dirs first (additive; stale files are pruned in step 4 so the
+#    still-active old index.html never dangles)
+Write-Host '[2/5] Syncing new assets to prod dir...' -ForegroundColor Yellow
+Get-ChildItem -Path $DistDir -Force | Where-Object { $_.Name -ne 'index.html' } | ForEach-Object {
+    Copy-Item -Recurse -Force $_.FullName $ProdRoot
+    Write-Host "  synced: $($_.Name)"
+}
 Write-Host ''
 
-# 4. Verify prod dir matches dist (file name sets)
-Write-Host '[4/4] Verifying artifact consistency...' -ForegroundColor Yellow
+# 3. Swap index.html last: at this point every asset it references already exists
+Write-Host '[3/5] Swapping index.html...' -ForegroundColor Yellow
+Copy-Item -Force (Join-Path $DistDir 'index.html') $IndexHtml
+Write-Host '  index.html updated'
+Write-Host ''
+
+# 4. Prune stale files in the mirror dirs (assets / tinymce) that the new build no
+#    longer ships. Only mirror dirs are touched -- prod-only dirs like pages/ are kept.
+Write-Host '[4/5] Pruning stale files...' -ForegroundColor Yellow
+function Remove-StaleFiles([string]$distDir, [string]$prodDir) {
+    if (-not (Test-Path $prodDir)) { return }
+    if (-not (Test-Path $distDir)) {
+        # Whole dir is gone from the build: remove it from prod
+        Remove-Item -Recurse -Force $prodDir
+        Write-Host "  removed dir: $($prodDir.Substring($ProdRoot.Length))"
+        return
+    }
+    $distNames = @(Get-ChildItem -Path $distDir -Recurse -File | ForEach-Object { $_.FullName.Substring($distDir.Length) })
+    $stale = @(Get-ChildItem -Path $prodDir -Recurse -File | Where-Object {
+        $_.FullName.Substring($prodDir.Length) -notin $distNames
+    })
+    foreach ($f in $stale) {
+        Remove-Item -Force $f.FullName
+        Write-Host "  removed: $($f.FullName.Substring($ProdRoot.Length))"
+    }
+    # Drop now-empty sub dirs (deepest first)
+    Get-ChildItem -Path $prodDir -Recurse -Directory |
+        Sort-Object { $_.FullName.Length } -Descending |
+        Where-Object { -not (Get-ChildItem -Path $_.FullName -Force) } |
+        ForEach-Object {
+            Remove-Item -Force $_.FullName
+            Write-Host "  removed empty dir: $($_.FullName.Substring($ProdRoot.Length))"
+        }
+}
+Remove-StaleFiles (Join-Path $DistDir 'assets')  $ProdAssetsDir
+Remove-StaleFiles (Join-Path $DistDir 'tinymce') (Join-Path $ProdRoot 'tinymce')
+Write-Host ''
+
+# 5. Verify prod dir matches dist (file name sets)
+Write-Host '[5/5] Verifying artifact consistency...' -ForegroundColor Yellow
 function Get-AssetNames([string]$dir) {
     if (-not (Test-Path $dir)) { return @() }
     return @(Get-ChildItem -Path $dir -Recurse -File | ForEach-Object { $_.FullName.Substring($dir.Length) })
 }
-$distNames  = Get-AssetNames (Join-Path $DistDir 'assets')
-$prodNames  = Get-AssetNames $ProdAssetsDir
-$distSet    = @($distNames | Sort-Object -Unique)
-$prodSet    = @($prodNames | Sort-Object -Unique)
+$distNames = Get-AssetNames (Join-Path $DistDir 'assets')
+$prodNames = Get-AssetNames $ProdAssetsDir
+$distSet   = @($distNames | Sort-Object -Unique)
+$prodSet   = @($prodNames | Sort-Object -Unique)
 
 $onlyDist = @($distSet | Where-Object { $_ -notin $prodSet })
 $onlyProd = @($prodSet | Where-Object { $_ -notin $distSet })