First of all, all osteosarcomas are malignant; osteosarcoma is a type of malignant tumor with no benign variant. Regarding the treatment of osteosarcoma, the first step is chemotherapy. After confirming the diagnosis through pathological examination and confirming it is osteosarcoma, The first step is chemotherapy, which can stabilize the tumor cells; Then, the main tissue is surgically removed, as well as the surrounding infiltrated soft tissue; The third step is to use chemotherapy again to eliminate the residual cancer cells. This treatment protocol of chemotherapy-surgery-chemotherapy is currently the most common and advanced method in the country. It can significantly improve the patient's survival rate, reduce the risk of amputation, and can also prevent the recurrence of osteosarcoma.