The finite element method is used to simulate the selective laser melting residual stress field of Al Si10 Mg powder. The finite element heat transfer model is established

and the laser heat source is regarded as a three-dimensional Gaussian heat source to realize the moving load on the powder bed. Considering the characteristic of the thermophysical parameters and laser energy absorption rate varying with temperature from the two types of material element properties of powder state and solid state. The indirect thermal-stress coupling analysis is carried out and the influence of laser power

scanning speed and preheating temperature of the substrate on the residual stress field is studied. The results show that the maximum residual stress appears in the contact position between base plate and powder bed

and the y-direction residual stress（parallel scanning direction）is larger than the x-direction residual stress（vertical scanning direction）;the Von Mises equivalent stress and the y-direction residual stress gradually increase as the laser power rise

but they gradually decrease as the scanning speed and the preheating temperature of base plate improve.