diff --git a/3rdparty/deepin-pdfium/src/dpdfdoc.cpp b/3rdparty/deepin-pdfium/src/dpdfdoc.cpp
index 2e593bba..c83e67b1 100755
--- a/3rdparty/deepin-pdfium/src/dpdfdoc.cpp
+++ b/3rdparty/deepin-pdfium/src/dpdfdoc.cpp
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2023 UnionTech Software Technology Co., Ltd.
+// SPDX-FileCopyrightText: 2023 - 2026 UnionTech Software Technology Co., Ltd.
 //
 // SPDX-License-Identifier: LGPL-3.0-or-later
 
@@ -245,7 +245,7 @@ bool DPdfDoc::save()
 
     QTemporaryDir tempDir;
 
-    QString tempFilePath = tempDir.path() + "/" + QUuid::createUuid().toString();
+    QString tempFilePath = tempDir.path() + "/" + QUuid::createUuid().toString(QUuid::WithoutBraces);
 
     saveWriter.setFileName(tempFilePath);
 
@@ -269,9 +269,10 @@ bool DPdfDoc::save()
 
     QString targetPath = d_func()->m_filePath;
 
-    // Extract directory and filename to create hidden backup file
+    // Use a UUID-only hidden file as backup to avoid long filename
+    // issues with NAME_MAX (255 bytes) on the backup path.
     QFileInfo fileInfo(targetPath);
-    QString backupPath = fileInfo.absolutePath() + "/." + fileInfo.fileName() + ".backup." + QUuid::createUuid().toString();
+    QString backupPath = fileInfo.absolutePath() + "/." + QUuid::createUuid().toString(QUuid::WithoutBraces);
 
     QFile targetFile(targetPath);