Abstract: In this work, specimens of single-track multi-layer K4648 nickel-based super alloy under different process parameters are prepared by laser melting deposition (LMD) technology, and the morphologies and hardness of the specimens are compared. The optimal process parameters are selected to print specimens for microstructure observation, tensile property test and friction and wear performance test to reveal the strengthening and toughening mechanism. The results show when the laser power is 550 and 600 W, the scanning speed 400 mm/min, and powder feeding speed 7 g/min, the forming qualities and hardness of the two groups of specimens are optimal. The microstructure of multi-track multi-layer LMD K4648 specimen is composed of equiaxed crystals, and the grains grow along the scanning/deposition direction. The tensile strength and yield strength of specimen by the laser power of 550 W are 10.30% and 19.46% higher than those of specimen by the laser power of 600 W, and the elongation is increased by 10.71%, indicating the specimen by the laser power of 550 W has better tensile properties. The hardness of specimen by the laser power of 550 W is 7.83% higher than that specimen by the laser power of 600 W, and its wear rate decreases by 21.57%, presenting the specimen by the laser power of 550 W has better wear-resisting property. The strengthening mechanism for the improvement of strength and wear resistance of K4648 nickel-based super alloy by the laser power of 550 W are grain strengthening, grain boundary strengthening and dislocation strengthening.