Objective To improve the corrosion resistance and wear resistance of AZ91D magnesium alloy. Methods Ni-P-SiC composite coating and Ni-P coating were directly fabricated by electroless plating using phosphoric acid + ammonium molybdate pickling and HF activation. For comparison, electroless Ni-P coating was prepared at the same time. The morphology, composition, structure, hardness, corrosion resistance and wear resistance of the two coatings were compared systematically. Results The cellular grains of coating were refined by adding SiC powder. SiC phase appeared in the Ni-P-SiC composite coating without changing the basic structure of Ni-P alloy. The hardness of the Ni-P-SiC composite coating reached up to 643HV. The corrosion current density increased slightly in terms of the Ni-P alloy coating. Conclusion Compared with the Ni-P coating, the corrosion resistance of the Ni-P-SiC composite coating declined slightly, but its wear resistance increased greatly.