A composition of a copper alloy for a laser cladding valve sheet is disclosed. The copper alloy includes a matrix structure and a hard phase, which includes 12 to 24 wt % of Ni, 2 to 4 wt % of Si, 8 to 30 wt % of Fe, more than 5 wt % and less than 10 wt % of Mo, 2 to 10 wt % of Al, and the balance Cu. The interfacial delamination may be suppressed in a fatigue environment by micronizing the hard phase and the distribution thereof, thereby improving fatigue resistance and wear resistance.