Large bone defects are formed after resection of bone tumors in the middle segment of long bones, and postoperative reconstruction is difficult. There are several reconstruction methods for mid-segment bone defects, including mid-segment prosthesis, allograft bone, autologous bone inactivation, induced membrane technique, and fibula graft reconstruction, and each method has its own advantages and disadvantages. Allogeneic bone combined with fibula graft with vascularized tip is now the more commonly used method to treat mid-segment bone defects, but its application is limited by the preservation conditions of allogeneic bone, antigenicity and technique of fibula graft with vascularization. Autologous bone inactivation preserves the shape of the bone while retaining the protein activity that induces bone growth, which facilitates bone healing, and its use is not limited by preservation conditions and source, so it is widely used in Asian countries. Our center has long used 20% hypertonic saline 62° constant temperature water bath for 30 minutes to inactivate bone tumors in the middle segment of long bones, and then replanted and reconstructed to treat bone tumors. Clinical results have proved that this method is an effective means of repairing tumors in the middle segment of long bones after resection because it can effectively inactivate tumor cells while preserving bone strength and inducing osteogenic ability.