Sacrum is an important bone structure through which a human trunk is connected with limbs. An upward side of the sacrum is formed into a lumbosacral joint with a lumbar vertebra and two sides are formed into a sacroiliac joint with a pelvis. The sacrum is provided with important sacral nerves inside and the sacroiliac joint is also a unique structure for connecting axial bones and lower limb bones. As a result, this site has a great impact on nerve functions and structure stability after excision. For patients suffering from sacral tumors, a combination of a radiotherapy, a chemotherapy and tumor excision is a first choice for most sacral tumors. However, the sacral tumors have the characteristics that the early symptoms are few and when being found, most are huge, so for the sacral tumors, the excision extension is relatively large in an operation; and meanwhile, it seriously damages the local stability, and after the excision, the recovery of stress conduction and the reconstruction of stability at a lumbosacral portion are directly associated with postoperative functions and life quality of the patients. To recover the lumbosacral portion, three most important structures are a lumbar lordosis, a posterior pelvic ring and an anterior vertebral column. Particularly for the patients who receive a total sacrectomy, a bone defect will cause that the human trunk and pelvis are interrupted and the patients after the operation have the problems, for example, they possibly cannot stand and walk, and cannot look after themselves. If the sacrum is not effectively reconstructed, serious subsidence of the lumbar vertebra and lumbosacral nerve stretch may occur after the operation. The above-mentioned reconstruction after the sacrectomy is a big difficult problem in the bone tumor field internationally. Currently, there are multiple sacral tumor excision and reconstruction operations, among which structural bone grafting reconstruction is the most common. The structural bone grafting reconstruction is mainly classified into two categories. One is the “church type” reconstruction, which refers to directly support an inferior lumbar vertebra onto iliums by means of an iliac screw and a screw-rod system. The above structural bone grafting reconstruction can achieve the bearing effect in a short time, but from long-term follow-up observation, the screw rod is broken or loosed easily, the bone is damaged, and the patients are trapped in the state that they cannot stand and walk and cannot look after themselves and must receive a fixation operation again. The other is to reconstruct via an iliac rod, which refers to connect iliums at the two sides by means of a bone graft or an implant, recover the posterior pelvic ring and connect with horizontal structures such as metal rod or bone graft by means of the screw-rod system, thereby reconstructing the stress conduction from the lumbar vertebra to the iliums. For the above structural bone grafting reconstruction, the early stability needs to be provided by a metal implant, but the long-term stability requires bony fusion. In this sense, biologic reconstruction is of great importance to the long-term stability of the lumbosacral portion. From the biomechanical point of view, as a torque is relatively long after the lumbar vertebra and the pelvis are fixed, the lumbosacral portion will bear relatively high stress and shear force. Moreover, the above reconstruction methods cannot implement the complete fusion of the lumbar vertebra and the pelvis, resulting in that the stress is mainly focused on the metal implant. In a long run, the metal implant will be broken due to fatigue, and thus, it loses the fixation effect and is pulled. Although the pulling of the metal implant can be reduced by applying methods such as bone graft, hydroxyapatite, bone cement and long screw, the problem of the fatigue break of the metal implant still hasn't been solved; and thus, it is difficult to implement the effective reconstruction.