Because of the necessity and importance of the study on optical fiber grating reconstruction, introduces the fiber Bragg grating(FBG) and studies the grating basic structure factors from the modulation principle about fiber Bragg grating's refractive index. Then deduces and expounds the transfer matrix method of FBG for uniformly modulated grating. Meanwhile, analyzes in detail the principle and the steps of layer peeling(LP) algorithm. Finally, based on LP algorithm, makes the related simulation and realizes the reconstructing of FBG, and shortens the group delay of the grating's reconstruction.