Overlapping peaks and low amplitude peaks in peak detection stage will lead to a high false detection rate. Therefore, a peak enhancement step is added before the peak detection stage to improve the resolution of overlapping peaks and increase the amplitude of the low amplitude peaks. The method in the model is to combine the classical nonlinear diffusion with the derivative spectra. In other word, the signal after the derivative spectrum enhancement is used as the initial signal of the classical nonlinear diffusion, and the enhanced signal is the result of the diffusion. As a test of the proposed mode, the performance of signal enhancement by the proposed model is compared with non-enhancement one, then compared with the performance of other signal enhancement methods. Results show that the proposed model is effective. Finally, the proposed model is applied to the enhancement of MALDI mass spectrometry.