Abstract: The copper-steel composite was prepared by laser cladding technology,the alloy layer,interface and matrix microstructure of the copper-steel composite were characterised,the mechanical properties and friction properties of the copper alloy layer and interface were detected. The results show that the fine crystal reinforcement caused by laser cladding and nickel diffusion to copper alloy layer make copper alloy layer show excellent mechanical properties,which is attributed to the presence of nickel in copper tin alloy generating complex ternary phase,the grain refinement weakens the tin segregation.Meanwhile,the increase of the grain boundaries separates the δ phases,and the disappearance of the continuous coarse δ phases is transformed into the scattered precipitation of intragranular and grain boundaries.The average tensile strength of the prepared copper-steel composite alloy layer is 502.3 MPa,the average yield strength is 356.6 MPa,the average elongation is 11.05%,the average section shrinkage is 8.55%,the average elastic modulus is 106.863 GPa,the average shear strength is 450.9 MPa,the interfacial bonding strength of the copper alloy is 549.7 MPa,and the friction coefficient is between 0.786-0.846.