Nickel based WC composite coating was prepared by the method of flame spraying and remelting, and its wear resistance was researched. The surface morphology of the coating after wear test was observed with scanning electric microscope, and the effects of WC volume fraction, the homogeneity of grain distribution, and the size of the packed powder grain on the wear were analyzed. The results showed that the hardness and wear resistance of the coating improve with WC volume fraction increasing, but the coating density lowers when WC volume fraction is too high, and the hardness and wear resistance decrease as a reaults. The distribution of WC grain with the blending method of polyethylene glycol (PEG) 400+ PEG2000+ethanol is most even, which decreases the degree of wear. Wear resistance of coating containing the same volume fraction of sub-micron WC powders is better than that of WC powders of micron size.