Parameter intunability in microwave photonic filter(MPF) limits its application in all-optical networks. A multi-parameter tunable design of a multi-channel MPF by utilizing the structural characteristics of the periodic array of a sampled fiber Bragg grating(FBG) is proposed, using optical mode coupling theory and matrix determinant to analyze the spectrum characteristics of the sampled FBG. The simulation model of multi-channel MPF based on fourth-order sampling FBG array is established, and the simulation results show that the channel bandwidth of MPF can be increased by increasing the refractive index change rate; the channel interval of MPF can be increased by increasing the optical path difference of adjacent FBG; the center wavelength of MPF can be tuned by adjusting the temperature of FBG, so that MPF can swich flexibly between low-pass, high-pass, band-pass and band-stop filters.