Abstract: The quantitative relationship between system energy consumption, specific energy consumption (indicating energy efficiency) and process parameters was established by analyzing the energy consumption composition and characteristics of selective laser melting (SLM) system. A process parameter optimization strategy for optimizing the energy efficiency was proposed. The results show that the contradiction between the cladding efficiency and the energy consumption should be considered in selecting the laser power. The reasonable increase of laser scanning speed could improve the cladding efficiency and shorten working time of laser cladding under the disadvantage of reducing the cladding channel size, and then reduce energy consumption. Larger powder-bed thickness and scanning speed, as well as smaller transverse overlap rate matching the appropriate laser power, could effectively reduce the specific energy consumption of the SLM system. Choosing a direction with a smaller height for stacking could shorten the interlayer time and reduce the energy consumption of the system.