解决方法：
import base64 part = MIMEText(open(fileName, ‘rb‘).read(), ‘base64‘, ‘UTF-8‘) part["Content-Type"] = ‘application/octet-stream‘ part.add_header(‘Content-Disposition‘, ‘attachment‘, filename= ‘=?utf-8?b?‘ + base64.b64encode(fileName.encode(‘UTF-8‘)) + ‘?=‘) 然后，中文显示正常！！！
原文：https://www.cnblogs.com/xiongzhe90/p/11578696.html