Abstract: In the process of γ energy spectrum measurement, how to smooth spectrum data effectively concerns the accuracies of determination of the peak channel address and the calculation of the peak area. Based on the wavelet analysis, the imperfections of key factors that influence the results of denoising (threshold selection method and threshold function) were analyzed and improved. The results show that the smoothness index and the ratio of energy of denoised energy spectrum and original energy spectrum for the improved wavelet threshold method are 0.985 3 and 0.999 8, respectively, and the denoising effect of the improved wavelet threshold method is better than that of other methods.