The invention discloses a space desample decoding method, which comprises the following steps: 1, inputting a coding video code scream, obtaining a DCT block through variable-length code decoding and inverse quantization coding, 2, for an intraframe coding code scream, dividing the DCT block into high-frequency information and low-frequency information, wherein the low-frequency information rebuilds an image with low distinguishability and outputs the image through inverse transform, for an interframe coding code scream, executing the following steps: dividing the DCT block into high-frequency information Res-H and low-frequency information Res-L, which respectively enter into a high-frequency loop and a low-frequency loop for motion compensation to obtain high-frequency information H-H and low-frequency information H-L, wherein at least one part of the high-frequency information Res-H is added with at least one part of the high-frequency information H-H, which obtains a high-frequency reference frame to be sent to a high-frequency frame memory for high-frequency motion compensation of subsequent frames, simultaneously, the low-frequency information Res-L and low-frequency H-L are plus to carry out inverse transform to obtain pixel area residual errors, and then are plus with the low-frequency information L-L to obtain a low-frequency reference frame which is sentto a low-frequency memory frame for low-frequency motion compensation, and an image with low distinguishability is rebuilt in the pixel area and is output.