Abstract: The laser cladding is a process of rapid heating and rapid cooling; the cladding layer is prone to produce thermal stress; it is easy to cause crack defects. Invar effect is the unique low expansion mechanism and unique structure and performance of Invar alloy. The use of low expansion alloy powder can significantly reduce crack defects in the cladding layer. The laser cladding of 42CrMo steel by using self-configured Fe-Ni-C alloy powder with invar effect was performed. The quality, microstructure, microhardness and wear performance of the cladding layer were studied under different process parameters. The results show that by laser cladding Fe-Ni-C alloy powder, a defect-free cladding layer with a flat surface can be obtained without cracks and porosity. By comparing the friction coefficient between the cladding layer and the substrate, it is found that the friction coefficient of the cladding layer is better than that of 42CrMo steel.