In order to improve the frame rate and the grey level of the midwave (MWIR) infrared scene projector,the optical systems scheme based on dual DMD (Digital micro mirror device) is presented. The optical systems include the illumination system and the collimating projection optics. The Kohler illumination is used to supply uniform illumination for the projector. The two aspheric lenses are used to simplify configuration of the illumination system. The TIR prism containing three sections are used to fold and connect the ray path of the illumination system and the collimating projection optics,meanwhile superposing the modulation of the two DMD. The collimating projection optics uses a re imaging configuration. The optimization of the collimating projection optics is accomplished by distributing the parameters of the lenses and using aspheric surfaces in the lenses. The F/number of the collimating projection optics is 0.94. The entrance pupil distance is 850mm. The angular resolution is 0.19 mrad. The results of the testing and simulation for the projector illustrate that the performances of the optical systems meet the requirements of the infrared scene projector.