往复机械设备振动的频率随时间变化 ,对这类振动信号的特征分析 ,有助于研究机器设备的运行状况。时频分布描述了信号幅值随时间和频率综合变化的信息。此外研究了典型的时频分析算法———STFT分布 ,比较了时频分析方法和传统信号分析方法的差异 ,并将时频分析方法应用于往复机械振动信号的特征提取 The frequency of vibration of reciprocating machinery changes with time. The characteristic analysis of such vibration signals helps to study the operation of machinery and equipment. Time-frequency distribution describes the signal amplitude with time and frequency of comprehensive changes in information. In addition, a typical time-frequency analysis algorithm --- STFT distribution is studied. The differences between the time-frequency analysis method and the traditional signal analysis method are compared. The time-frequency analysis method is applied to the feature extraction of the reciprocating machine vibration signal