Abstract: Plasma spraying Ni Al WC alloy layer on the surface of chrome cast iron and alloy layer's micro structure and properties are studied. The analysis items include chemical composition, phase structure, average microhardness, wear resistance and corrosion resistance. The experimental results indicate that metallurgical combination has been achieved completely between the spraying layer and the surface of chrome cast iron, and that the chemical composition and micro structure in the surface layer of the sample have been changed basically, and that the microhardness, the wear resistance, the corrosion resistance in the surface layer are increased by a large margin.