We establish a source simulation system by using a digital micromirror device (DMD) as a display device and investigate the imaging distortion of an optical system. First, we illustrate the general design of the system and calculate the object-space depth and shape variables caused by the different attitude azimuth of the DMD by using geometric optics. Then, we choose the optimum attitude. Subsequently, we simulate the system by using optical software, establish the imaging distortion measurement template and algorithms, and analyze the installation error of the DMD's attitude angle. The analysis shows that the imaging distortion is about 1.3% caused by the 0.3° pitch angle or azimuth deviation. Finally, guided by the design and simulation results, the optical path of the experimental system is completed. The results show that the average distortion corresponding to the maximum field of view is 0.385%.