In order to solve the problem of long development cycle and low efficiency caused by repeated repair and testing of die when using traditional empirical method in the stretch forming process of large-size double-curvature skin, for three different stretch forming process parameters, the AI-Form Stretch Forming (AISF) finite element software was used to simulate the sheet metal stretch forming, and the optimal combination of stretch forming parameters was explored to predict the strain distribution condition of sheet metal during the stretch forming process. The results show that when the die height is 1000 mm and the upper die pressure is increased to 100 kN, the surface deformation of the stretch-formed sheet metal is uniform with the maximum strain of 0.15 and the maximum die clearance less than 1 mm. Through process testing verification, the experimental result is in good agreement with the simulation result with the maximum error of less than 2.8%, which effectively reduces the wrinkling during sheet metal stretch forming process. Thus, the results show that high-quality skin parts are obtained at the optimum stretching loading parameters, reducing the development cycle and improving the production efficiency.