The invention proposes a space-time multiplexing method for suppressing computer-generated holographic display speckle noise. According to the method, a plurality of computer-generated holograms are generated by a pixel separation method, and the reproduction of the computer-generated holograms is performed by the space-time multiplexing method according to light polarization state characteristic and visual persistence characteristic of a human eye. The computer-generated holograms is reproduced according to groups, the computer-generated holograms in the same group employ reproduced light with different polarization states, the suppression of speckle nose of Airy disc image points which are stacked is achieved by space multiplexing of a plurality of space light modulators, for the computer-generated holograms in different groups, the Airy disc image points are prevented from being stacked in space by a time multiplexing method, and the generation of the speckle noise is further prevented; and meanwhile, by a visual persistence effect of the human eye, the complete viewing of recording information is achieved.