Membrane transfer matrix theory was used to study the influence between modulation refractive index and transmission characteristics of optical Fiber Bragg Grating (FBG). The influence of grating refractive index modulation amplitude,grating length and modulation method on reflectivity,the reflection peak wavelength and half width of FBG is calculated based on transfer matrix theory. The results show that characteristics of FBG analyzed by the Membrane layer transfer matrix theory,the traditional transfer matrix method and the coupled-mode theory is consistent;high modulation length,low modulation amplitude can obtain good FBG reflection peak,and the main reflection peak position need adjusted by the modulation cycle. The method is verified through the experiment and theoretical analysis of the main reflection peak of FBG in the 1550 nm. Membrane layer transfer matrix method can be applied to the FBG aided design for its simple calculation formula,fast speed compared with traditional methods.