Abstract: In order to achieve high-quality hologram reconstruction based on digital micro-mirror device (DMD), gray scale adjustment characteristics and Fresnel diffraction characteristics of DMDs were described in detail. Then, the principle of holographic display based on DMD was analyzed. Finally, high-quality hologram was reconstructed. The results demonstrate holographic display was improved obviously after grayscale-adjustment. The results are helpful for the display of computer generated hologram based on digital micro-mirror device.