Digital Micro-mirror Device (DMD) is a kind of reflecting spatial light modulator which has most virtue such as operating on the whole wave bands, high resolution, high frame rates, wide dynamic range, complete digitalization, small cubage and wide thermal range. A dynamic infrared scene generating and emulation system can be constructed of it with producing high quality dynamic infrared image. This paper presents the operating principle of DMD and the basic principle of dynamic IR scene projection system based on DMD. The choice of illumination and optical path in the system is analyzed in details. A modified device with a infrared window is obtained, its transmissive band is 0.4~12μm and almost all pixel is intact. Several images generated by the system is shown and the characteristics of spectrum output is tested. Major technical parameters of the DMD dynamic infrared scene projection system is given in the last section.