A video decoding method, a video encoding method, and related apparatuses. The method includes: determining a current video frame; determining a reference frame corresponding to the current video frame from video frames that have been decoded, and obtaining a target quantity of blocks that are decoded in a skip mode in the reference frame and a total block quantity of blocks in the reference frame; determining, according to a relationship between the target quantity and the total block quantity, a target resolution used for decoding the current video frame; and decoding the current video frame by using the target resolution. For different current video frames, different resolutions used for decoding can be adaptively selected, to simplify operations of determining the target resolution for decoding the current video frame, thereby resolving the technical problem of relatively low video encoding and decoding efficiency caused by complex processing operations in the related art.