Abstract: Arc spraying and plasma cladding process was used to prepare the aluminum composite coating.The microstructure and phase structures of the clad alloy layer and the interface of alloy layer and steel matrix composites were analyzed.The results show that the tight alloy layer without pore and inclusion is obtained, and the coating and the steel are metallurgically compacted.The clad alloy layer consists of phase Fe₃Al, FeAl, α-Fe and Al₂O₃.Microhardness of the clad alloying layer will be 514 HV.