Theoretical model of the continuous wave radar life signal was improved by introducing the biological electric theory . Using the lifting wavelet transform and the improved threshold function denoising technique, the radar life signal of the strong noise was processed. The signal to noise ratio and the mean square error of the radar life signal of the 166.67 mm wavelength are optimized from 2.046 8 and 6.6969 to 1.763 9 and 0.9099, and 8.57 mm wavelength are optimized from 0.942 6 and 1.9806 to 2.541 8 and 1.286 0. The result indicates that the theoretical model of the continuous wave radar life signal is consistent with the actual situation and the denoising scheme can be applied to radar wave at different wavelengths.