DMD(Digital Micromirror Device) is originally designed for visible light spectrum, so it brings lots of problems when DMD is operated under infrared optics. To solve these problems, we provide a telecentric projection optical engine architecture, including projection optical system and illumination optical system. This optical engine employs Kohler telecentric illumination structure, and a field lens is introduced to separate the illumination beams and projection beams. This optical engine has good performance with compact structure, uniform lighting and high energy utilization efficiency.