Stellite 3, Stellite 21 and new Co-based alloy (Co-3) coatings are prepared on the 316 stainless steel surface by laser cladding. The microstructure and phase composition of the cladding layers are analysed and the microhardness distribution and abrasion resistance mechanism are also studied. The experimental results show that the microstructure of the Co-3 is homogeneous, compact, and without cracks and cavity, where the main phases consist of (Co,W)3C, Cr23C6, Cr7C3, and Co3Mo. The average microhardness of the cladding layer is about 624 HV0.2, which is more than 3 times higher than that of the substrate. The abrasion resistance performance of Co-3 is superior to that of the 316 substrate. Under the load of 0~150 N condition, when the scratching length s≤3.3 mm, the main scratch mechanism is plastic deformation; when the scratching length 3.3＜s≤6.9 mm, the main scratch mechanism is grain sliding and crack formation caused by plastic deformation; when the scratching length s＞6.9 mm, the main scratch mechanism is crack propagation and plastic removal.