Example point cloud encoding apparatus and point cloud decoding apparatus are provided for effectively encoding and decoding point cloud data. The point cloud encoding apparatus is configured for obtaining auxiliary information of a union occupancy map corresponding to a point cloud group, where the point cloud group includes N frames of point clouds, N≥2, and N is an integer. The union occupancy map is a union set of occupancy maps of N patches having a matching relationship in the N frames of point clouds, and the auxiliary information of the union occupancy map is used to determine auxiliary information of the N patches. A syntax element is encoded into a bitstream, where the syntax element includes the auxiliary information of the union occupancy map.