To develop computer generated holographic video (CGHV) technology utilizing the digital micromirror device (DMD), the holographic coding methods have been investigated. Basis on digital micromirror device physical microstructure, two dimensional discrete micromirror pixels, blazed diffraction gratings of rotated mirrors and its pulse width modulation working principle are discussed. The following factors have been considered, namely, digital micromirror device's resolution, mirror size, pitch, rotating angle, incident angles of reference wave and diffracting conditions, etc. In order to match the hologram to the spatial light modulating properties of digital micromirror device and fulfill the requirements of computer generated holographic video, the sampling method on interference plane, phase compensation technique and no-bias binary hologram coding method are put forward. The experimental results show that the methods have adjusted the diffractive direction of object wave, the diffraction energy concentrated on object wave, improved the quality of reconstruction, increased the utilization ratio of diffraction energy, and improved the efficiency of holographic code.