diff --git a/blade-service/blade-transport/src/main/java/org/springblade/transport/service/impl/InvoiceReceiptServiceImpl.java b/blade-service/blade-transport/src/main/java/org/springblade/transport/service/impl/InvoiceReceiptServiceImpl.java
index 96e9ed49..c4632d3f 100644
--- a/blade-service/blade-transport/src/main/java/org/springblade/transport/service/impl/InvoiceReceiptServiceImpl.java
+++ b/blade-service/blade-transport/src/main/java/org/springblade/transport/service/impl/InvoiceReceiptServiceImpl.java
@@ -1301,6 +1301,10 @@ public class InvoiceReceiptServiceImpl extends BaseServiceImpl<InvoiceReceiptMap
 				throw new ServiceException("调用BFI文件下载失败：" + readBfiJsonMessage(bfiResponse));
 			}
 			String fileName = Func.isBlank(item.name()) ? invoiceNo + ".pdf" : item.name();
+			// BFI 文件流统一回 octet-stream：PDF 版式须显式声明 MIME，否则浏览器 blob 不渲染、查看退化为静默下载
+			if (fileName.endsWith(".pdf") && (Func.isBlank(contentType) || contentType.contains("octet-stream"))) {
+				contentType = "application/pdf";
+			}
 			// 文件名按 RFC 5987 编码（+ 号转 %20），中文/特殊字符不乱码
 			String encodedName = URLEncoder.encode(fileName, StandardCharsets.UTF_8).replace("+", "%20");
 			response.setContentType(Func.isBlank(contentType) ? "application/pdf" : contentType);