Abstract: The laser scanning micro electromechanical device projection system is realized by the two-dimensional deflection characteristics of micro electromechanical device and the laser diode as the light source. Compared with the traditional micro-projection technology, the micro-projection display system based on the micro electromechanical device has the advantages of small size, low energy consumption and high image contrast. According to the characteristics of the components, the laser beam was collimated, concentrated and homogenized. The post-scanning system of the objective lens was designed by using the reflection deflection characteristics of two-dimensional micro electromechanical device, and the scanning methods as well as the pixel arrangement were optimally analyzed. The design results show that the size of the image plane is 104mm×59mm, and the single-pixel point geometric radius is within 186 μm when 80% energy is included. The resolution of the system can reach 558×314 pixel, and the refresh rate is 30Hz. The design results can be used in the small projection systems such as vehicle head-up display system, and can also provide reference for similar designs in the future.