diff --git a/src/main/java/cn/lihongjie/coal/file/service/FileService.java b/src/main/java/cn/lihongjie/coal/file/service/FileService.java
index b0a6ccea..1272a1ab 100644
--- a/src/main/java/cn/lihongjie/coal/file/service/FileService.java
+++ b/src/main/java/cn/lihongjie/coal/file/service/FileService.java
@@ -25,6 +25,7 @@ import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.io.FilenameUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.tika.Tika;
+import org.apache.tika.config.TikaConfig;
 import org.jetbrains.annotations.NotNull;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
@@ -55,6 +56,7 @@ public class FileService extends BaseService<FileEntity, FileRepository> {
     @Autowired private FileMapper mapper;
     @Autowired private ConversionService conversionService;
     private final Tika tika = new Tika();
+    TikaConfig config = TikaConfig.getDefaultConfig();
 
     @Value("${spring.profiles.active}")
     private String activateProfile;
@@ -112,7 +114,8 @@ public class FileService extends BaseService<FileEntity, FileRepository> {
             String sortKey,
             String code,
             String remarks,
-            String url, String base64) {
+            String url,
+            String base64) {
 
         long size = 0;
         InputStream fis = null;
@@ -127,10 +130,13 @@ public class FileService extends BaseService<FileEntity, FileRepository> {
             size = out.size();
         } else if (StringUtils.isNotBlank(base64)) {
 
-            fis = new ByteArrayInputStream(Base64.getDecoder().decode(base64.replace("data:image/png;base64,", "")));
+            fis =
+                    new ByteArrayInputStream(
+                            Base64.getDecoder()
+                                    .decode(base64.replace("data:image/png;base64,", "")));
             size = fis.available();
 
-        }else {
+        } else {
             throw new BizException("文件为空");
         }
 
@@ -153,12 +159,28 @@ public class FileService extends BaseService<FileEntity, FileRepository> {
                                 Ctx.currentUser().getOrganizationId(),
                                 StringUtils.defaultIfBlank(dir, "public")));
         InputStream inputStream = fis;
-        fileEntity.setObjectId(
-                UUID.randomUUID() + "." + FilenameUtils.getExtension(name.replace(":", "_")));
+        String extension = FilenameUtils.getExtension(name.replace(":", "_"));
+
         try (inputStream) {
             fileEntity.setMimeType(tika.detect(inputStream));
         }
 
+        // if file ext is empty, get from mime type
+
+        try {
+
+            if (StringUtils.isBlank(extension)) {
+                extension =
+                        config.getMimeRepository()
+                                .getRegisteredMimeType(fileEntity.getMimeType())
+                                .getExtension().replace(".", "");
+            }
+        } catch (Exception e) {
+            log.warn("获取文件扩展名失败", e);
+        }
+
+        fileEntity.setObjectId(UUID.randomUUID() + "." + extension);
+
         String objectKey = getObjectKey(fileEntity);
 
         fileEntity.setPublicUrl(uploadToOSS(objectKey, fis));