In order to observe high dynamic scene effectively and in real time,an imaging system based on digital micromirror device as a spatial light modulator was designed.The capability of digital micromirror device was improved in increasing the dynamic range of imaging system by improving the driving timing of digital micromirror device.To tackle the distortion error of the optical system,polynomial fitting was employed to acquire the mapping relationship between digital micromirror device and imaging sensor.Finally,in order to resolve the problem of poor visuality when using ordinary light adjusting algorithm,tone mapping operator was introduced to generate a light adjusting template and image with better visuality was acquired.The results indicate that the dynamic range of traditional imaging system can be increased by 66 dB under the condition of 10 frames per second and the total dynamic range of the imaging system reachs 126 dB.Morever,the precision of using digital micromirror device to control imaging sensor is up to 0.69 pixel,bright part and dark part in a high dynamic range scene can be displayed simultaneously in one image after light adjusting and the entropy of image collected after light adjusting inreased.The imaging system meet the requirement of real time observation in high dynamic range scene.