Disclosed in the implementations of the present disclosure are a mapping method, an encoder, a decoder, and a computer storage medium. The method may include: determining an intra prediction mode used at the time of encoding or decoding a current block; mapping, if the intra prediction mode is a MIP mode, the MIP mode to a first non-MIP mode; and mapping, if the intra prediction mode is a non-MIP mode, the non-MIP mode to a second MIP mode.