Abstract: Manufacturing material 30CrMo of multifunctional cross was used as the base material.On the surface of 30CrMo specimen, cobalt-base alloy coatings of HS113, 625 and Co-112 were prepared by argon arc welding, coating of Ni60 prepared by spray welding, coating of WC-12Co was prepared by HVOF.The five kinds of erosion behavior of the coatings were studied by homemade erosion tester.The effect of microstructure and microhardness on erosion capability was analyzed, surface appearance of coatings was also observed after the test.The results showed that both of weightlessness and reduction increasd linearly along with the erosion time.Erosion resistance of HS113 coating was superior to the other four kinds of coating.Microstructure, hardness, etc all could affect the erosion resistance of the coating.