Abstract: For ubiquitous problems in the technology of clay model, such as a longer manufacturing cycle and some difficulties in controlling precision, therefore, stereo lithography 3D printing can be used in the manufacture of automotive body as a whole. Experimental results show that 3D printing technology can compress the manufacturing cycle into a few days, it is suitable for an effective evaluation of the product shape, it can improve the overall efficiency of automobile body manufacturing, and 3D printing technology ultimately enables to reduce R & D costs. With the help of UG and Magics software, the flexibility can be improved in the choice of design parameters, ultimately achieving three-dimensional modeling of an automobile body and importing STL files. There are spot diameter, scan pitch, scanning speed, layer thickness and other factors based on the accuracy of the forming member. According to curve-based features for the automobile body, there is a way to derive the optimum layer thickness calculation method based on Bezier curves to achieve an optimal thickness.