由于科学技术的飞速发展，使银行卡的使用范围不断扩大，因而出现银行卡用卡安全问题 。本文主要介绍了银行卡密码泄露漏洞，对利用录音设备对手机、电话等按键式密码输入终端进录音盗取银行卡密码的不法行为进行技术分析，利用MATLAB软件编程对按键式密码输入终端的按键音进行音频分析，基于短时能量和过零率对所采集的音频文件进行端点检测，提取出单个拨号音，然后对处理后的音频进行频谱分析、对比，从而识别按键式密码输入终端的按键音。-Due to the rapid development of science and technology, the use of bank cards continued to expand, and thus to a bank card with a card security issues. This paper describes the bank card password disclosure vulnerability on the use of recording equipment on the phone, telephone touchtone input terminal password into the recording steal bank card passwords wrongful conduct technical analysis using MATLAB software programming for touchtone input terminal password keys sound audio analysis, based on short-term energy and zero-crossing rate of the acquired endpoint detection audio files, extract single dial tone, and then processed audio spectrum analysis, comparison, to identify key touchtone input terminal password sound.