Abstract: In this study, Cold Metal Transfer Technology was used to cladding GH4169 alloy on the surface of Q235 steel. The microstructure and mechanical properties of the cladding layer, substrate and near the fusion line before and after heat treatment of composite plates were studied.The test results show that when the welding current is 370 A, GH4169 has good metallurgical combination with Q235 without macroscopic defects. After the graded heat treatment, lamellar martensite structure appears in grain Q235, and Laves phase changes from long strip to granular in GH4169. The microhardness of the substrate increases from 154 HV to 172 HV.The microhardness of GH4169 cladding layer increases from 240 HV to 422 HV, and the impact energy of the sample also increases from 32 J to 55 J.