The present disclosure describes a three-dimensional object segmentation method and device, and medium, and relates to the field of computer vision (CV) technologies of an artificial intelligence (AI) technology. The method includes obtaining, by a device, a point cloud of a three-dimensional object. The device includes a memory storing instructions and a processor in communication with the memory. The method includes determining, by the device, three scaling directions of the point cloud; scaling, by the device, positions of points in the point cloud along the three scaling directions to obtain a scaled point cloud, so that the scaled point cloud has the same scale in the three scaling directions; and segmenting, by the device, the three-dimensional object based on the scaled point cloud to obtain a segmentation result.