diff --git a/m3tpostprocess.py b/m3tpostprocess.py
new file mode 100644
index 0000000..bcb1c58
--- /dev/null
+++ b/m3tpostprocess.py
@@ -0,0 +1,129 @@
+import re
+import os
+import math
+
+
+ELLIPSIS = re.compile(r'\.{3,}')
+ELLIPSIS_ZH = re.compile(r'…+')
+HYPHEN_ZH = re.compile(r'—+')
+HALF_FULL_MAP = (
+    (',', '，'),
+    ('.', '。'),
+    ('!', '！'),
+    ('?', '？'),
+    ('~', '～'),
+    ('(', '（'),
+    (')', '）'),
+    (':', '：'),
+    (';', '；'),
+    ('-', '—'),
+    ('ー', '—'),
+    ('&', '＆'),
+    ('%', '％'),
+    ('・', '·'),
+)
+MIXED_RULE1 = re.compile(r'[，。、]+([…—～]+)')
+MIXED_RULE2 = re.compile(r'([…—～]+)[，。、]+')
+MIXED_RULE3 = re.compile(f'([…—～])[…—～]+')
+# 平假名
+HIRAGANA = re.compile(r'[\u3040-\u309F]+')
+# 片假名
+KATAKANA = re.compile(r'[\u30A0-\u30FF]+')
+# 狗屎wamsoft在scn里拉的指令
+SCN_SPECIAL = re.compile(r'(%(?:[^%;]*;|r)|#[0-9a-fA-F]{6,8};)')
+
+
+def process_line(data: str) -> str:
+    # 使用省略号替换连续的点
+    data = ELLIPSIS.sub(lambda m: '…' * math.ceil(len(m.group(0)) / 3), data)
+    for half, full in HALF_FULL_MAP:
+        data = data.replace(half, full)
+    #，。、和…—~混用
+    data = MIXED_RULE1.sub(lambda m: m.group(1), data)
+    data = MIXED_RULE2.sub(lambda m: m.group(1), data)
+    # 混用时…—~只保留一个
+    data = MIXED_RULE3.sub(lambda m: m.group(1) * len(m.group(0)), data)
+    # 省略号和破折号统一只留一对
+    data = ELLIPSIS_ZH.sub('……', data)
+    data = HYPHEN_ZH.sub('——', data)
+    # 删除所有平假名
+    data = HIRAGANA.sub('', data)
+    # 删除所有片假名
+    data = KATAKANA.sub('', data)
+    data = data.replace('！？', '？！')
+    data = data.replace('。」', '」')
+    return data
+
+
+def process_scn_line(data: str) -> str:
+    parts = SCN_SPECIAL.split(data)
+    for i in range(len(parts)):
+        if i % 2 == 0:
+            parts[i] = process_line(parts[i])
+            # 特殊处理 。%command;」
+            if i > 0 and parts[i].startswith('」'):
+                while parts[i - 2].endswith('。'):
+                    parts[i - 2] = parts[i - 2][:-1]
+    return ''.join(parts)
+
+
+def process_m3t(m3t_path, scn=False):
+    lines = []
+    line_num = 0
+    for line in open(m3t_path, "r", encoding="utf-8"):
+        line = line.strip()
+        line = line.replace('\u200b', '')  # 移除零宽空格
+        if line_num == 0:
+            line = line.lstrip("\ufeff")  # 移除可能的BOM
+        line_num += 1
+        if line.startswith("●") or line.startswith("△"):
+            data = line[1:].strip()
+            if scn:
+                ndata = process_scn_line(data)
+            else:
+                ndata = process_line(data)
+            if data != ndata:
+                print(f"{m3t_path}:{line_num}: {data} -> {ndata}")
+                line = line[0] + " " + ndata
+        lines.append(line)
+    return lines
+
+
+def save_lines(m3t_path, lines):
+    with open(m3t_path, "w", encoding="utf-8") as f:
+        for line in lines:
+            f.write(line + "\n")
+
+
+def process_m3t_file(m3t_path, target_path=None, dry_run=False, scn=False):
+    lines = process_m3t(m3t_path, scn)
+    if not dry_run:
+        if target_path is None:
+            save_lines(m3t_path, lines)
+        else:
+            os.makedirs(os.path.dirname(target_path), exist_ok=True)
+            save_lines(target_path, lines)
+
+
+def recursive_process_m3t(m3t_path, target_path=None, dry_run=False, scn=False):
+    for root, dirs, files in os.walk(m3t_path):
+        for file in files:
+            full_path = os.path.join(root, file)
+            output_path = None
+            if target_path is not None:
+                output_path = os.path.join(target_path, file)
+            process_m3t_file(full_path, output_path, dry_run, scn)
+
+
+if __name__ == "__main__":
+    from argparse import ArgumentParser
+    parser = ArgumentParser(description="Post-process M3T files.")
+    parser.add_argument("m3t_path", help="Path to M3T file/directory.")
+    parser.add_argument("target_path", nargs="?", default=None, help="Path to save processed M3T file/directory. If not specified, overwrite original files.")
+    parser.add_argument("-d", "--dry-run", action="store_true", help="Only show changes without saving.")
+    parser.add_argument("--scn", action="store_true", help="Process SCN lines with special rules.")
+    args = parser.parse_args()
+    if os.path.isdir(args.m3t_path):
+        recursive_process_m3t(args.m3t_path, args.target_path, args.dry_run, args.scn)
+    else:
+        process_m3t_file(args.m3t_path, args.target_path, args.dry_run, args.scn)
diff --git a/m3tpostprocess_unittest.py b/m3tpostprocess_unittest.py
new file mode 100644
index 0000000..f0a2413
--- /dev/null
+++ b/m3tpostprocess_unittest.py
@@ -0,0 +1,27 @@
+from m3tpostprocess import process_line, process_scn_line
+
+
+def test_process_line(src, expected):
+    processed = process_line(src)
+    if processed != expected:
+        raise AssertionError(f"Expected: {expected}, but got: {processed}")
+
+
+def test_process_scn_line(src, expected):
+    processed = process_scn_line(src)
+    if processed != expected:
+        raise AssertionError(f"Expected: {expected}, but got: {processed}")
+
+
+if __name__ == "__main__":
+    test_process_line("Hello....", "Hello……")
+    test_process_line("……。", "……")
+    test_process_line("，。……", "……")
+    test_process_line("…—~", "……")
+    test_process_line("----~...", "——")
+    test_process_line("~~--", "～～～～")
+    test_process_line("!?!?", "？！？！")
+    test_process_line("これはテストです测试。", "测试。")
+    test_process_line("「地形模型。」", "「地形模型」")
+    test_process_scn_line("「地形模型。%command;」", "「地形模型%command;」")
+    test_process_scn_line("%cmd;25%的可能。", "%cmd;25％的可能。")