For the problems of large motion capture data and the difficulty of editing key frames, the paper proposed a technique to introduce wavelet transform into key frames extraction and motion editing. The proposed technique deals with the motion capture data as signal processing, decomposes the signal into high frequency signals and low frequency signals, and disposes the coefficients by semisoft threshold function, and extracts key frames through setting different threshold. After extracting the key frames, the key frames animation is reconstructed by the interpolation technique in order to generate new human motion sequence. In motion editing, the high frequency signals are adjusted so as to enhance the characteristics of motion, further improving the technique of motion editing. The experiment demonstrates this technique is of good application, the extracted key frames have recapitulation, and after the motion editing, the reality of motion can be ensured to some extent.