The invention relates to a human body part segmentation method and system based on SPECT imaging, based on a bone imaging data matrix, a human body region is extracted from a bone imaging image to obtain effective information of the bone imaging data matrix, the calculation amount is reduced, and the segmentation precision is improved. Then the human body area is divided into a head area, a chest area, a pelvic bone area and a leg area based on the data matrix corresponding to the human body area and human morphological characteristics, then the chest area is divided into a trunk area, a left upper limb and a right upper limb based on the data matrix corresponding to the chest area, and finally based on the data matrix corresponding to the leg area, the leg area is divided into the left lower limb and the right lower limb, so that the human body is divided into the head, the trunk, the four limbs, the pelvis and other parts, accurate segmentation of the human body parts is achieved, and accurate segmentation of the head, the trunk, the four limbs, the pelvis and other parts can be effectively conducted on any SPCET bone imaging image.