diff --git a/Mac/Base.lproj/Main.storyboard b/Mac/Base.lproj/Main.storyboard
index f98f71c9..c8d938d3 100644
--- a/Mac/Base.lproj/Main.storyboard
+++ b/Mac/Base.lproj/Main.storyboard
@@ -1775,10 +1775,10 @@ CA
                             <modifierMask key="keyEquivalentModifierMask"/>
                             <menu key="submenu" title="Export" id="LoU-Gc-oM3">
                                 <items>
-                                    <menuItem title="PDF" alternate="YES" keyEquivalent="P" id="UcZ-Ne-qv1">
+                                    <menuItem title="HTML" alternate="YES" keyEquivalent="H" id="Ge6-vi-x3q">
                                         <modifierMask key="keyEquivalentModifierMask" control="YES"/>
                                         <connections>
-                                            <action selector="exportPdf:" target="XfG-lQ-9wD" id="DiT-Ue-MTm"/>
+                                            <action selector="exportHtml:" target="XfG-lQ-9wD" id="pZF-N2-y4v"/>
                                         </connections>
                                     </menuItem>
                                     <menuItem title="Image" alternate="YES" keyEquivalent="I" id="GsA-uj-XlT">
@@ -1787,10 +1787,10 @@ CA
                                             <action selector="exportImage:" target="XfG-lQ-9wD" id="CHV-dY-HtD"/>
                                         </connections>
                                     </menuItem>
-                                    <menuItem title="HTML" alternate="YES" keyEquivalent="H" id="Ge6-vi-x3q">
+                                    <menuItem title="PDF" alternate="YES" keyEquivalent="P" id="UcZ-Ne-qv1">
                                         <modifierMask key="keyEquivalentModifierMask" control="YES"/>
                                         <connections>
-                                            <action selector="exportHtml:" target="XfG-lQ-9wD" id="pZF-N2-y4v"/>
+                                            <action selector="exportPdf:" target="XfG-lQ-9wD" id="DiT-Ue-MTm"/>
                                         </connections>
                                     </menuItem>
                                     <menuItem title="MiaoYan PPT PDF" alternate="YES" keyEquivalent="P" id="DhD-mk-T1u">
diff --git a/Mac/View/MPreviewView.swift b/Mac/View/MPreviewView.swift
index 7a22c457..5e9ab426 100644
--- a/Mac/View/MPreviewView.swift
+++ b/Mac/View/MPreviewView.swift
@@ -72,7 +72,8 @@ class MPreviewView: WKWebView, WKUIDelegate, WKNavigationDelegate {
                 menuItem.identifier?.rawValue == "WKMenuItemIdentifierTranslate" ||
                 menuItem.identifier?.rawValue == "WKMenuItemIdentifierSearchWeb" ||
                 menuItem.identifier?.rawValue == "WKMenuItemIdentifierShareMenu" ||
-                menuItem.identifier?.rawValue == "WKMenuItemIdentifierLookUp" {
+                menuItem.identifier?.rawValue == "WKMenuItemIdentifierLookUp"
+            {
                 menuItem.isHidden = true
             }
         }
@@ -550,7 +551,8 @@ class MPreviewView: WKWebView, WKUIDelegate, WKNavigationDelegate {
 
 class HandlerCheckbox: NSObject, WKScriptMessageHandler {
     func userContentController(_ userContentController: WKUserContentController,
-                               didReceive message: WKScriptMessage) {
+                               didReceive message: WKScriptMessage)
+    {
         guard let position = message.body as? String else { return }
         guard let note = EditTextView.note else { return }
 
@@ -590,7 +592,8 @@ class HandlerCodeCopy: NSObject, WKScriptMessageHandler {
     }
 
     func userContentController(_ userContentController: WKUserContentController,
-                               didReceive message: WKScriptMessage) {
+                               didReceive message: WKScriptMessage)
+    {
         let message = (message.body as! String).trimmingCharacters(in: .whitespacesAndNewlines)
 
         HandlerCodeCopy.selectionString = message
@@ -601,7 +604,8 @@ class HandlerSelection: NSObject, WKScriptMessageHandler {
     public static var selectionString: String?
 
     func userContentController(_ userContentController: WKUserContentController,
-                               didReceive message: WKScriptMessage) {
+                               didReceive message: WKScriptMessage)
+    {
         let message = (message.body as! String).trimmingCharacters(in: .whitespacesAndNewlines)
 
         HandlerSelection.selectionString = message
@@ -611,7 +615,8 @@ class HandlerSelection: NSObject, WKScriptMessageHandler {
 // 用于解决ppt模式下背景颜色变化左侧边框颜色的适配
 class HandlerRevealBackgroundColor: NSObject, WKScriptMessageHandler {
     func userContentController(_ userContentController: WKUserContentController,
-                               didReceive message: WKScriptMessage) {
+                               didReceive message: WKScriptMessage)
+    {
         guard let vc = ViewController.shared() else { return }
         let message = (message.body as! String).trimmingCharacters(in: .whitespacesAndNewlines)
         if message == "" {
diff --git a/Mac/View/MarkdownView.swift b/Mac/View/MarkdownView.swift
index 9b591874..32af9c21 100644
--- a/Mac/View/MarkdownView.swift
+++ b/Mac/View/MarkdownView.swift
@@ -70,7 +70,9 @@ open class MarkdownView: WKWebView {
             return "html {font-size: \(UserDefaultsManagement.presentationFontSize)px} :root { --text-font: \(UserDefaultsManagement.previewFontName), sans-serif; --code-text-font: \(codeFontName),sans-serif; } #write { max-width: 100%;}"
         } else {
             let paddingStyle = UserDefaultsManagement.isOnExport ? " padding-top: 24px" : ""
-            return "html {font-size: \(UserDefaultsManagement.previewFontSize)px; \(paddingStyle)} :root { --text-font: \(UserDefaultsManagement.previewFontName), sans-serif; --code-text-font: \(codeFontName),sans-serif; } #write { max-width: \(UserDefaultsManagement.previewWidth);}"
+            let writeCSS = UserDefaultsManagement.isOnExportHtml ? " max-width: 800px; margin: 0 auto" : "max-width: \(UserDefaultsManagement.previewWidth);"
+
+            return "html {font-size: \(UserDefaultsManagement.previewFontSize)px; \(paddingStyle)} :root { --text-font: \(UserDefaultsManagement.previewFontName), sans-serif; --code-text-font: \(codeFontName),sans-serif; } #write { \(writeCSS)}"
         }
     }
 
@@ -239,7 +241,8 @@ extension MarkdownView: WKNavigationDelegate {
 
 class HandlerCopyCode: NSObject, WKScriptMessageHandler {
     func userContentController(_ userContentController: WKUserContentController,
-                               didReceive message: WKScriptMessage) {
+                               didReceive message: WKScriptMessage)
+    {
         let message = (message.body as! String).trimmingCharacters(in: .whitespacesAndNewlines)
         let pasteboard = NSPasteboard.general
         pasteboard.declareTypes([NSPasteboard.PasteboardType.string], owner: nil)
@@ -249,14 +252,16 @@ class HandlerCopyCode: NSObject, WKScriptMessageHandler {
 
 class HandlerMouseOver: NSObject, WKScriptMessageHandler {
     func userContentController(_ userContentController: WKUserContentController,
-                               didReceive message: WKScriptMessage) {
+                               didReceive message: WKScriptMessage)
+    {
         NSCursor.pointingHand.set()
     }
 }
 
 class HandlerMouseOut: NSObject, WKScriptMessageHandler {
     func userContentController(_ userContentController: WKUserContentController,
-                               didReceive message: WKScriptMessage) {
+                               didReceive message: WKScriptMessage)
+    {
         NSCursor.arrow.set()
     }
 }