diff --git a/pkg/filesystem/validator.go b/pkg/filesystem/validator.go
index 06f4c05..94a735b 100644
--- a/pkg/filesystem/validator.go
+++ b/pkg/filesystem/validator.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"github.com/HFO4/cloudreve/pkg/util"
 	"path/filepath"
+	"strings"
 )
 
 // ValidateFileSize 验证上传的文件大小是否超出限制
@@ -26,7 +27,7 @@ func (fs *FileSystem) ValidateExtension(ctx context.Context, fileName string) bo
 		return true
 	}
 
-	ext := filepath.Ext(fileName)
+	ext := strings.ToLower(filepath.Ext(fileName))
 	// 无扩展名时
 	if len(ext) == 0 {
 		return false
diff --git a/pkg/filesystem/validator_test.go b/pkg/filesystem/validator_test.go
index ed28181..6d68f07 100644
--- a/pkg/filesystem/validator_test.go
+++ b/pkg/filesystem/validator_test.go
@@ -86,5 +86,6 @@ func TestFileSystem_ValidateExtension(t *testing.T) {
 	asserts.False(fs.ValidateExtension(ctx, "1.jpg.png"))
 	asserts.True(fs.ValidateExtension(ctx, "1.txt"))
 	asserts.True(fs.ValidateExtension(ctx, "1.png.jpg"))
+	asserts.True(fs.ValidateExtension(ctx, "1.png.jpG"))
 	asserts.False(fs.ValidateExtension(ctx, "1.png"))
 }