This application discloses a point cloud encoding processing method, a point cloud decoding processing method, and a related device. A point cloud encoding processing method according to an embodiment of this application includes: performing, by an encoder, transform processing based on a transform tree structure corresponding to a to-be-encoded point cloud, to obtain attribute transform coefficients of a to-be-encoded node in the transform tree structure, where the attribute transform coefficients of the to-be-encoded node include a first attribute transform coefficient corresponding to a first channel and a second attribute transform coefficient corresponding to a second channel; performing, by the encoder, prediction encoding processing on the second attribute transform coefficient based on the first attribute transform coefficient, to obtain a residual attribute transform coefficient corresponding to the second attribute transform coefficient; and performing, by the encoder, encoding processing on the residual attribute transform coefficient, to obtain a first encoding result.