Abstract: In some scenarios, very bright objectives and very dark objectives exist at the same time. The traditional imaging device can not detect these objectives, and then high dynamic range image acquiring system is needed to detect them. Digital Micro-mirror Devices(DMD) is used to get high dynamic range image, which is the most advanced technology at present. In this paper, a pixel level high dynamic range imaging system is designed based on DMD. The system is composed of optical system, mechanical system, DMD pixel level dimming algorithm and imaging unit. The secondary imaging system is used in the optical system. The first imaging optical structure is image space telecentric system, and the second imaging optical structure is magnification 1:1 quasi-symmetric system. Wrapping technology of optical elements and centering machining process are used in mechanical system, and the optical assembly precision reaches second level. The method searching for single DMD pixel's controlling weight is used in dimming algorithm. The science class 12 bit sCMOS and 8 bit CCD can be used simultaneously in imaging unit. The correctness of the system is proved by the prototype. The image dynamic range can reach 140 dB, much higher than 78 dB dynamic range of traditional cameras.