The selective laser melting (SLM) process of AlSi10Mg alloy was numerically simulated by simfactory additive 4.0 software. The effects of scanning speed, scanning distance, substrate temperature and laser power on the deformation behavior of AlSi10Mg alloy and the residual stress on the interface between the part and substrate were studied. The results show that the tensile deformation is mainly in the x direction, while the shrinkage deformation is in the y and z directions; With the increase of substrate temperature (25-225 ℃), laser power (250-450 W), scanning speed (900-1 300 mm/s) and scanning spacing (40-80 mm/s). The results show that the residual stress of the interface decreases first and then increases with the increase of the stress. Through simulation, the best printing parameters are the substrate temperature: 180 °C, the scanning speed is 1 100 mm/s, the laser power is 450 W, and the scanning distance is 70 μm.