diff --git a/electron/main.js b/electron/main.js
index 3a64fe1..e8f005d 100644
--- a/electron/main.js
+++ b/electron/main.js
@@ -303,7 +303,7 @@ ipcMain.handle("print-pdf", async (event, pdfDataOrUrl, printOptions = {}) => {
     const duplexMode = printOptions?.duplex;
     // pdf-to-printer 使用 side 选项，而不是 duplex
     // side 可选值: "simplex" | "duplex" | "duplexshort" | "duplexlong"
-    const sideOption = duplexMode ? "duplex" : "simplex";
+    const sideOption = duplexMode ? "duplexlong" : "simplex";
     log.info(
       `准备打印PDF: ${pdfFilePath}, 打印机: ${targetPrinterName || "默认打印机"
       }, 双面打印: ${duplexMode ? "是" : "否"}`