diff --git a/README.md b/README.md
index 0430877..edfdb2a 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,6 @@
 ## Fork
 
 - [JamieDummy/NCM_dump](https://github.com/JamieDummy/NCM_dump): 增加 GUI
-
 - [mnilzg/ncmdump](https://github.com/mnilzg/ncmdump): 使用 numpy 大幅提高性能 
 
 
@@ -34,7 +33,7 @@ $ python ncmdump.py
 ### 更多选项
 ```
 $ python app.py -h
-usage: ncmdump [-h] [-f format] [-o output] [-d] [input [input ...]]
+usage: ncmdump [-h] [-f format] [-o output] [-d] [-c | -s] [input [input ...]]
 
 positional arguments:
   input       ncm file or folder path
@@ -44,6 +43,8 @@ optional arguments:
   -f format   customize naming format
   -o output   customize saving folder
   -d          delete source after conversion
+  -c          overwrite file with the same name
+  -s          skip conversion if file exist
 ```
 
 > 自定义命名参数: %artist%, %title%, %album%
diff --git a/app.py b/app.py
index 905b49e..2dfd483 100644
--- a/app.py
+++ b/app.py
@@ -24,9 +24,18 @@ parser.add_argument(
     help = 'customize saving folder'
 )
 parser.add_argument(
-    '-d', dest = 'delete', action='store_true',
+    '-d', dest = 'delete', action = 'store_true',
     help = 'delete source after conversion'
 )
+group = parser.add_mutually_exclusive_group()
+group.add_argument(
+    '-c', dest = 'cover', action = 'store_true',
+    help = 'overwrite file with the same name'
+)
+group.add_argument(
+    '-s', dest = 'skip', action = 'store_true',
+    help = 'skip conversion if file exist'
+)
 args = parser.parse_args()
 
 def validate_name(file_name):
@@ -63,7 +72,7 @@ def name_format(path, meta):
     name += '.' + meta['format']
     folder = args.output if args.output else os.path.dirname(path)
     save = os.path.join(folder, name)
-    save = validate_collision(save)
+    if not (args.cover or args.skip): save = validate_collision(save)
     return save
 
 if args.output:
@@ -76,26 +85,26 @@ if args.output:
         exit()
 
 files = []
-for item in args.input:
-    item = os.path.abspath(item)
-    if not os.path.exists(item):
+for path in args.input:
+    path = os.path.abspath(path)
+    if not os.path.exists(path):
         continue
-    if os.path.isdir(item):
-        files += [os.path.join(item, _file) for _file in os.listdir(item) if os.path.splitext(_file)[-1] == '.ncm']
+    if os.path.isdir(path):
+        files += [os.path.join(path, name) for name in os.listdir(path) if os.path.splitext(name)[-1] == '.ncm']
     else:
-        files += [item]
+        files += [path]
 
 if sys.version[0] == '2':
-    files = [file_name.decode(sys.stdin.encoding) for file_name in files]
+    files = [path.decode(sys.stdin.encoding) for path in files]
 
 if not files:
     print('empty input')
     exit()
 
-for _file in files:
+for path in files:
     try:
-        _save = ncmdump.dump(_file, name_format)
-        print(os.path.split(_save)[-1])
-        if args.delete: os.remove(_file)
+        save = ncmdump.dump(path, name_format, args.skip)
+        if save: print(os.path.split(save)[-1])
+        if args.delete: os.remove(path)
     except KeyboardInterrupt:
         exit()
\ No newline at end of file
diff --git a/ncmdump.py b/ncmdump.py
index 2cd9c5d..0b3beb2 100644
--- a/ncmdump.py
+++ b/ncmdump.py
@@ -13,7 +13,7 @@ import os
 from Crypto.Cipher import AES
 from mutagen import mp3, flac, id3
 
-def dump(input_path, output_path = None):
+def dump(input_path, output_path = None, skip = True):
 
     output_path = (lambda path, meta : os.path.splitext(path)[0] + '.' + meta['format']) if not output_path else output_path
     core_key = binascii.a2b_hex('687A4852416D736F356B496E62617857')
@@ -71,6 +71,7 @@ def dump(input_path, output_path = None):
 
     # media data
     output_path = output_path(input_path, meta_data)
+    if skip and os.path.exists(output_path): return
     m = open(output_path,'wb')
     data = bytearray(f.read())
 
@@ -120,17 +121,18 @@ if __name__ == '__main__':
     if len(sys.argv) > 1:
         files = sys.argv[1:]
     else:
-        files = [file_name for file_name in os.listdir('.') if os.path.splitext(file_name)[-1] == '.ncm']
+        files = [name for name in os.listdir('.') if os.path.splitext(name)[-1] == '.ncm']
+    
     if sys.version[0] == '2':
-        files = [file_name.decode(sys.stdin.encoding) for file_name in files]
+        files = [path.decode(sys.stdin.encoding) for path in files]
 
     if not files:
         print('please input file path!')
         
-    for file_name in files:
+    for path in files:
         try:
-            dump(file_name)
-            print(os.path.split(file_name)[-1])
+            dump(path)
+            print(os.path.split(path)[-1])
         except Exception as e:
             print(e)
             pass
\ No newline at end of file