Working principle of optical comb filter is introduced.By changing parameters of sampling fiber grating and simulating its reflective spectrum by Matlab.Four kinds of optical comb filters based on sampling fiber grating are debugged.Wavelet denoising principle is introduced.In order to optimize design of sampling grating comb filter

denoising processing is carried out by using wavelet analysis on reflection spectrum is proposed.Automatic one-dimensional denoising is carried out using db6 wavelet.It not only filtering major noise interference

but also play a certain inhibition affect in the side-lobe interference of signal.Smooth reflective spectrum can be obtained.