In order to solve the problem of large size and poor filtering perform ance of traditional filters,a new type of multi-channel photonic crystal filte r is designed.The structure is based on the coupling principle of photonic cryst al line defect waveguide and ring resonator.The structure and transmission char acteristics of the filter are analyzed by using the plane wave expansion method and the finite difference time domain method respectively.The results show that the filter has an excellent frequency selection function,which can achieve mul ti-wavelength output of 1.5717μm,1.5834μm,1.5084μm,1.5195μm,the transmit tance of each channel is more than 95%.It can be seen that the filter has excel lent filtering performance,which can meet the requirements of high integration and high efficiency of filters for signal processing in the future,and we can k now there is a great prospect of application in the field of optical communicati ons.