The fabrication technics of fiber grating coupler(FGC) based on fused biconical taper coupler and phase mask fiber grating technics is designed through the improvement of trial-manufacture and the analysis of influencing factors in detail. The FGC which can be used as optical add-drop multiplexer(OADM) is successfully produced and the experiments of optical add multiplexer(OAM)/ optical drop multiplexer(ODM) are all carried out. The valuable reference for the design and fabrication of FGC is provided.