Abstract: The laser scanning projector can realize the precise position projection of the wire frame contour for the components to be assembled, and can also greatly improve the problems of low precision and low efficiency caused by the traditional assembly method. In order to realize the 3D digital model laser projection in IGES format that can be read directly in the independently developed laser scanning projection system, the multi-feature image primitive extraction and the automatic files generation method were studied. In this method, the data features such as points, lines, and surfaces of the wire frame graphics to be projected were extracted and stored as the cellular in the .ply format file. The delay control of the numerical control switch and the control of the 2D vibrating mirror track were carried out by the .ply format file, which realized the more intelligent control of the laser scanning projection. The projection experiment of 12 IGES format image primitives verify that the proposed method can achieve the clear projection of all the image primitives, and the laser contour width is better than 0.3 mm. The assembly efficiency of the workshop and the assembly precision can be improved by using this new projection system.