Osteosarcoma usually presents with pain, which is often severe, persistent, and most pronounced at night. The local skin temperature may also increase, accompanied by venous obstruction. It is a malignant tumor of the bone, most commonly located near the proximal part of the tibia or the distal part of the femur. The main symptom is pain, and a definite diagnosis can be made through radiographic examination, such as sunlight exposure, Codman's triangle, etc. In its early stages, osteosarcoma can metastasize. If there is no pain, it may be due to individual variations in the disease. However, the first symptoms of malignant bone tumors are usually pain and a palpable mass. Radiographic examinations will show changes. If osteosarcoma is confirmed and there is no pain, it could be related to the disease not having progressed to a more severe stage, possibly indicating an early stage. Early aggressive surgical treatment is recommended, such as limb-sparing surgery, devitalization and reimplantation, or prosthetic implantation. Another option is amputation. Osteosarcoma has a relatively high chance of metastasizing to the lungs; therefore, early surgery, early diagnosis, and rapid chemotherapy are essential, as these can significantly increase the five-year survival rate.