A reference frame decoding method includes obtaining a first reference frame, where the first reference frame is a first picture frame on which decoding reconstruction has been performed or a first interpolated picture frame obtained by pixel interpolation on the first picture frame, parsing a bitstream to obtain mapping parameters, determining to-be-determined coefficients of a preset mapping function according to the mapping parameters, obtaining, in the first reference frame according to the mapping function whose to-be-determined coefficients have been determined, a first pixel unit having a mapping relationship with a second pixel unit of a second reference frame, and assigning a pixel value of the first pixel unit to the second pixel unit.