diff --git a/app/src/main/java/io/legado/app/help/storage/BookWebDav.kt b/app/src/main/java/io/legado/app/help/storage/BookWebDav.kt
index 9a299512f..5af0231f0 100644
--- a/app/src/main/java/io/legado/app/help/storage/BookWebDav.kt
+++ b/app/src/main/java/io/legado/app/help/storage/BookWebDav.kt
@@ -38,7 +38,7 @@ object BookWebDav {
             return url
         }
 
-    suspend fun initWebDav(): Boolean {
+    private suspend fun initWebDav(): Boolean {
         val account = appCtx.getPrefString(PreferKey.webDavAccount)
         val password = appCtx.getPrefString(PreferKey.webDavPassword)
         if (!account.isNullOrBlank() && !password.isNullOrBlank()) {
@@ -122,19 +122,16 @@ object BookWebDav {
         }
     }
 
-    suspend fun exportWebDav(path: String, fileName: String) {
+    suspend fun exportWebDav(byteArray: ByteArray, fileName: String) {
         try {
             if (initWebDav()) {
                 // 默认导出到legado文件夹下exports目录
                 val exportsWebDavUrl = rootWebDavUrl + EncoderUtils.escape("exports") + "/"
                 // 在legado文件夹创建exports目录,如果不存在的话
                 WebDav(exportsWebDavUrl).makeAsDir()
-                val file = File("${path}${File.separator}${fileName}")
                 // 如果导出的本地文件存在,开始上传
-                if (file.exists()) {
-                    val putUrl = exportsWebDavUrl + fileName
-                    WebDav(putUrl).upload("${path}${File.separator}${fileName}")
-                }
+                val putUrl = exportsWebDavUrl + fileName
+                WebDav(putUrl).upload(byteArray)
             }
         } catch (e: Exception) {
             Handler(Looper.getMainLooper()).post {
diff --git a/app/src/main/java/io/legado/app/ui/book/cache/CacheViewModel.kt b/app/src/main/java/io/legado/app/ui/book/cache/CacheViewModel.kt
index 4a060c991..28c7d1500 100644
--- a/app/src/main/java/io/legado/app/ui/book/cache/CacheViewModel.kt
+++ b/app/src/main/java/io/legado/app/ui/book/cache/CacheViewModel.kt
@@ -16,6 +16,7 @@ import io.legado.app.help.storage.BookWebDav
 import io.legado.app.utils.*
 import splitties.init.appCtx
 import java.io.File
+import java.nio.charset.Charset
 
 
 class CacheViewModel(application: Application) : BaseViewModel(application) {
@@ -38,20 +39,24 @@ class CacheViewModel(application: Application) : BaseViewModel(application) {
         }
     }
 
+    @Suppress("BlockingMethodInNonBlockingContext")
     private suspend fun export(doc: DocumentFile, book: Book) {
         val filename = "${book.name} by ${book.author}.txt"
-        val content = getAllContents(book)
-        DocumentUtils.createFileIfNotExist(doc, filename)
-            ?.writeText(context, content)
-        if (appCtx.getPrefBoolean(PreferKey.webDavCacheBackup, false)) {
-            FileUtils.createFileIfNotExist(
-                File(FileUtils.getCachePath()),
-                filename
-            ).writeText(content) // 写出文件到cache目录
-            // 导出到webdav
-            BookWebDav.exportWebDav(FileUtils.getCachePath(), filename)
-            // 上传完删除cache文件
-            FileUtils.deleteFile("${FileUtils.getCachePath()}${File.separator}${filename}")
+        DocumentUtils.delete(doc, filename)
+        DocumentUtils.createFileIfNotExist(doc, filename)?.let { bookDoc ->
+            val stringBuilder = StringBuilder()
+            context.contentResolver.openOutputStream(bookDoc.uri, "wa")?.use { bookOs ->
+                getAllContents(book) {
+                    bookOs.write(it.toByteArray(Charset.forName(AppConfig.exportCharset)))
+                    stringBuilder.append(it)
+                }
+            }
+            if (appCtx.getPrefBoolean(PreferKey.webDavCacheBackup, false)) {
+                // 导出到webdav
+                val byteArray =
+                    stringBuilder.toString().toByteArray(Charset.forName(AppConfig.exportCharset))
+                BookWebDav.exportWebDav(byteArray, filename)
+            }
         }
         getSrcList(book).forEach {
             val vFile = BookHelp.getImage(book, it.third)
@@ -67,10 +72,17 @@ class CacheViewModel(application: Application) : BaseViewModel(application) {
 
     private suspend fun export(file: File, book: Book) {
         val filename = "${book.name} by ${book.author}.txt"
-        FileUtils.createFileIfNotExist(file, filename)
-            .writeText(getAllContents(book))
+        val bookPath = FileUtils.getPath(file, filename)
+        val bookFile = FileUtils.createFileWithReplace(bookPath)
+        val stringBuilder = StringBuilder()
+        getAllContents(book) {
+            bookFile.appendText(it, Charset.forName(AppConfig.exportCharset))
+            stringBuilder.append(it)
+        }
         if (appCtx.getPrefBoolean(PreferKey.webDavCacheBackup, false)) {
-            BookWebDav.exportWebDav(file.absolutePath, filename) // 导出到webdav
+            val byteArray =
+                stringBuilder.toString().toByteArray(Charset.forName(AppConfig.exportCharset))
+            BookWebDav.exportWebDav(byteArray, filename) // 导出到webdav
         }
         getSrcList(book).forEach {
             val vFile = BookHelp.getImage(book, it.third)
@@ -86,23 +98,18 @@ class CacheViewModel(application: Application) : BaseViewModel(application) {
         }
     }
 
-    private suspend fun getAllContents(book: Book): String {
+    private suspend fun getAllContents(book: Book, append: (text: String) -> Unit) {
         val useReplace = AppConfig.exportUseReplace
         val contentProcessor = ContentProcessor(book.name, book.origin)
-        val stringBuilder = StringBuilder()
-        stringBuilder.append(book.name)
-            .append("\n")
-            .append(context.getString(R.string.author_show, book.author))
+        append("${book.name}\n${context.getString(R.string.author_show, book.author)}")
         appDb.bookChapterDao.getChapterList(book.bookUrl).forEach { chapter ->
             BookHelp.getContent(book, chapter).let { content ->
                 val content1 = contentProcessor
                     .getContent(book, chapter.title, content ?: "null", false, useReplace)
                     .joinToString("\n")
-                stringBuilder.append("\n\n")
-                    .append(content1)
+                append.invoke("\n\n$content1")
             }
         }
-        return stringBuilder.toString()
     }
 
     private fun getSrcList(book: Book): ArrayList<Triple<String, Int, String>> {
diff --git a/app/src/main/java/io/legado/app/utils/DocumentUtils.kt b/app/src/main/java/io/legado/app/utils/DocumentUtils.kt
index 860c25f18..4a4341a0d 100644
--- a/app/src/main/java/io/legado/app/utils/DocumentUtils.kt
+++ b/app/src/main/java/io/legado/app/utils/DocumentUtils.kt
@@ -5,6 +5,7 @@ import android.database.Cursor
 import android.net.Uri
 import android.provider.DocumentsContract
 import androidx.documentfile.provider.DocumentFile
+import java.nio.charset.Charset
 import java.util.*
 
 
@@ -16,6 +17,11 @@ object DocumentUtils {
         return parent.findFile(fileName)?.exists() ?: false
     }
 
+    fun delete(root: DocumentFile, fileName: String, vararg subDirs: String) {
+        val parent: DocumentFile? = createFolderIfNotExist(root, *subDirs)
+        parent?.findFile(fileName)?.delete()
+    }
+
     fun createFileIfNotExist(
         root: DocumentFile,
         fileName: String,
@@ -47,8 +53,13 @@ object DocumentUtils {
 
     @JvmStatic
     @Throws(Exception::class)
-    fun writeText(context: Context, data: String, fileUri: Uri): Boolean {
-        return writeBytes(context, data.toByteArray(), fileUri)
+    fun writeText(
+        context: Context,
+        data: String,
+        fileUri: Uri,
+        charset: Charset = Charsets.UTF_8
+    ): Boolean {
+        return writeBytes(context, data.toByteArray(charset), fileUri)
     }
 
     @JvmStatic
@@ -143,8 +154,8 @@ data class DocItem(
 }
 
 @Throws(Exception::class)
-fun DocumentFile.writeText(context: Context, data: String) {
-    DocumentUtils.writeText(context, data, this.uri)
+fun DocumentFile.writeText(context: Context, data: String, charset: Charset = Charsets.UTF_8) {
+    DocumentUtils.writeText(context, data, this.uri, charset)
 }
 
 @Throws(Exception::class)