For the high temperature and high rotational speed working conditions of K418 superalloy impeller, the problems of deformation out of tolerance and reduction of mechanical properties after remanufacture for layer become the research focus. Basing on the optimized process of waveform modulation pulsed laser, the Inconel 718 alloy layer was remanufactured. The metallographic microscope, SEM, XRD, EDS, microhardness, and dynamic balance testing machine were used to research the microstructure morphology, phase structure, interface composition distribution, basic mechanical properties of Inconel 718 layer. The test results show, there is metallurgical bonding between the cladding layer and the substrate. The middle layer is a coarse dendrite, there is a 30~45 degree angle between the coarse dendrite and the laser scanning direction. From the middle of the forming layer to the top and bottom, the coarse dendrite degenerate into equiaxed and cellular crystals.The microhardness of the forming layer is 410~440 HV0.1, which is slightly higher than the substrate. A small amount of Laves phase is precipitated in the grains and intergranular, which reduces the impact on the hard-brittleness of the forming layer, the friction and wear coefficient is slightly lower than that of the matrix, but the requirements of remanufacture is still met.