Composite coating was prepared by spraying the HD590 rich-Al dope on Zn-Al coating. Comparing the adhesion intensity, abrasion resistance, micro-morphology of composite coating with Zn-Al coating, and their anticorrosion performance were studied by salt spray test, marine platform outdoor exposure and seawater periodic spraying test. The results show that the adhesion intensity of composite coating is improved 30% than Zn-Al coating, the abrasion resistance is excellent and the thickness settles for precision of fasteners; The composite coating exhibits obviously better anticorrosion performance than Zn-Al coating in salt spray and marine environment. The corrosion mechanism is that composite coating protects substrate steel by combining action of sheet shield, passivating and cathodal protection; In the anticorrosive process, the rich-Al coating activating dissolves and exerts sacrificial anode effects, also it enhances the cathodal protection by change the corrosion potential of composite coating to more negative.