Abstract: Denoising and edge preserving is a contradiction in image processing,denoising filter often lose the high frequency part of the signal,However,the edge information based mainly on high-frequency information.This paper introduces a new method-nonlinear complex diffusion method,the method by combining free Schrodinger equation will be the traditional anisotropic diffusion equation is extended to complex number field,complex number domain real signal can be very good filtering,the imaginary part of complex diffusion item add shock filter,this method overcomes the shortcomings of the traditional edge detection methods edge preserving ability difference.The test results show that:the algorithm has good noise immunity and edge retention,edge detection effect is good.