The two most commonly used fabrication methods of phase-shifted fiber Bragg grating, namely the stepped exposure method (or shielded method) and the phase mask moving method are described. Physical mechanisms of the two methods to introduce phase shift are comparatively analyzed. Using the theoretical model of transfer matrix method numerical simulation of the transmission spectra of phase shift fiber Bragg grating is done, and cross-reference experiments are carried out. The results show that the phase shift of the grating is related to the non-exposed segments of length and core refractive index modulation amount and it′s hard to accurately control in stepped method. While the phase shift is controlled in an amount of 0~2π range and easier to achieve π phase shift grating production in phase mask moving method using Piezo nano-positioning system.