冲击故障的振动响应信号是时变的 ,用传统的诊断方法一般难以进行早期发现和诊断。本文基于小波包对时变信号的多分辨分解和重构能力以及 CONE时频分布对时信号的优良描述特性 ,发展了基于小波包的时频分析方法。经试验和现场监测数据的分析和验证 ,说明该方法能够从很强的基础振动信号中提取清晰直观的冲击故障特征 ,可以实现冲击故障的早期诊断 Vibration response to impact failure signals are time-varying, with the traditional diagnostic methods generally difficult to early detection and diagnosis. Based on the wavelet packet’s multiresolution decomposition and reconstruction ability against time-varying signals and the excellent characterization of time-frequency distribution of CONE, a time-frequency analysis method based on wavelet packet is developed. The analysis and verification of the experimental and field monitoring data show that this method can extract clear and intuitive impact failure characteristics from the strong fundamental vibration signals and make early diagnosis of impact failure