Abstract: CoCrW alloy deposition layer was prepared on the surface of DZ125 alloy by laser deposition manufacturing technology,the influence rule of heat input on the crack of heat affected zone was studied,and the microstructure,microhardness distribution and friction and wear performance of the deposited samples were analyzed. The results show that high heat input makes the low melting point eucrystal phase melt,leading to crack initiation and expansion. A crack-free deposition layer is prepared by reducing the laser power and reducing the thermal input.The bottom of the deposition layer is columnar crystals that grow along the deposition height direction,the middle is heterogeneous crystals,and the top is chaotic equiaxial crystals. The phase of deposition layer mainly consists of γ-Co,CrCo,M₆C and Cr₂₃C₆. The average microhardness of the bottom,middle and top of the deposition layer is 4%,10%and 18%higher than that of the matrix.The wear mechanism of the deposition layer is grinding grain wear. The average friction coefficient,wear amount,wear rate,and the surface roughness value after wear are all reduced compared with those of the matrix. The friction and wear performance of the deposition layer is better than that of the matrix.