As a key component of the infrared imaging semi-physical simulation system for airborne optoelectronic products, how to obtain an infrared image closer to the real scene has become the key to the entire infrared imaging system semi-physical simulation system.For infrared dynamic scene projectors, the design of the optical system plays a key role in the imaging fidelity of the infrared simulation scene and target. According to the current usage requirements, this paper designed a medium wave infrared dynamic scene projection system based on DMD. To meet the requirements of the current semi-physical simulation experiments of optoelectronic products, a 1024 × 768 DMD chip was used as the scene modulator.In view of the fact that the dynamic scene projector was to be installed on a turntable, the collimating optical system was designed with a long exit pupil distance and a large exit pupil aperture. The collimating optical system has an exit pupil distance of 600mm, an exit pupil aperture of φ56mm, and a field of view of 6°.The final designed dynamic scene projector could achieve 100Hz dynamic scene generation and could be synchronized externally. The temperature simulation range was -10°C ~ + 300°C, the minimum temperature resolution was 0.1°C, and the gray level was 256. This medium wave dynamic scene projector had been successfully applied to the debugging and testing of several optoelectronic products and semi-physical simulation experiments, which significantly improved the research and development efficiency and shortened the research and development cycle.