The particles reinforced multi-pass Ni60CuMoW composite coatings are fabricated by optimizing laser cladding process on the surface of 45# steel. The microstructure, particles phase distribution and structure features are characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS). The micro hardness distribution and wear resistance of heat treatment composite coatings are measured by microscopic hardness tester and disc-pin dry friction and wear apparatus. The influence of heat treatment on wear mechanism is analyzed. The results show that the precipitation composite carbide and boride after tempering treatment have a good metallurgical bonding with 45# steel substrate in the range of 0.3~0.8 mm from interface. The composite coatings has the characteristics of integrality dimension distribution uniformry and high density. Compared with the 45# steel matrix, the average microhardness of the laser cladding Ni60CuMoW composite coatings before and after heat treatment increases by 4.9 times and 5.8 times, and the wear resistance increases by 1.1 times and 2.9 times, respectively.