Aiming at the problem that the quality of a reproduced image is not high due to speckle noise and aliasing phenomena in the pure phase hologram generation process, the invention provides a pure phasehologram generation method capable of improving the quality of the reproduced image. According to the invention, through rasterized object sampling, the method makes the most of the aliasing phenomenon to enable the amplitude distribution on the holographic surface to be uniform, and the loss information of the generated pure phase hologram is reduced, so that the original object can be completelyreproduced, and the reproduced image quality of the pure phase hologram is effectively improved. The method is simple and good in effect, and has great application potential in current popular AR display and projection display.