The work aims to explore the relationship between crack initiation and element segregation for the problems of laser cladding crack initiation and element segregation on K418 alloy surface and then repair the crack and control the segregation by the post-treatment process. The Inconel718 alloy was deposited on the surface of K418 alloy by laser cladding. The sensitivity of the crack during the cladding was analyzed based on the thermal properties of the matrix and the cladding material and the interface element matching. The segregation of alloy elements caused the initiation and propagation of cracks. The formation of thermal cracks in the matrix was related to the massive carbonitrides precipitated in the heat-affected zone, and the cracks of cladding layer were related to the irregular chain Laves phase precipitated between dendrites. The cladding layer was post-treated by laser remelting process. The test results showed that the microstructure after remelting was dense, the grains were fine and uniform, and there were no obvious defects such as cracks and sticky powder. The size and quantity of carbonitride and Laves phase due to element segregation in the heat affected zone and the cladding layer of the matrix were reduced. The friction coefficient of the cladding after remelting was 0.55, and the specific gravity was reduced by 49.5% before melting, which showed good antifriction. The wear rate was 3.15×10-4 mm3/(N?mm), the specific gravity was decreased by 37.5% before melting, and the wear resistance was improved. Laser remelting technology can heal the crack of Inconel718 alloy on K418 by laser cladding and significantly reduce the degree of elemental segregation of the coating.