Key forming parameters of laser engineering net shaping are laser power, scanning speed and stratification height. The relationship between the key parameters and residual stress must be mastered, because the residual stress influences the forming quality and deformation. Mastering the relationship is an effective way to reduce residual stress and to choose forming parameters. Using the life and death element technology and thermo-mechanical coupled field model, 8 groups of different key parameters of the laser engineering net shaping of titanium alloy are computed. The distribution cloud of the residual stress is obtained and three samples are selected. Through the multivariate regression of different key parameters and the residual stress, the multiple regression equation is obtained. The validity of the multiple regression equation is proved by finite element analysis and experiment. The multiple regression analysis is the effective way to reduce the time of simulation and experience of the different key parameters and to estimate the residual stress of the established parameters.