As a common malignant bone tumor, osteosarcoma is usually treated by surgical resection. However, the bone defects caused by surgery are difficult to heal, and the possibility of osteosarcoma recurrence can also be increased by the residual tumor cells. Therefore, a Nd-doped mesoporous borosilicate bioactive glass-ceramic bone cement was developed for repair of bone defects and synergistic therapy of osteosarcoma. Firstly, as photothermal agent and drug carrier, Nd-doped mesoporous borosilicate bioactive glass-ceramic (MBGC-xNd) microspheres were prepared through Sol-Gel method and solid-state reaction. Then MBGC-xNd microspheres were mixed with sodium alginate (SA) solution to prepare injectable bone cement (MBGC-xNd/SA). The results showed that Nd³⁺ endows microspheres with controllable photothermal properties, and microspheres loaded with doxorubicin (DOX) showed sustained drug release behavior. In addition, the drug release from drug-loaded bone cement was significantly accelerated with the increase of temperature, indicating that the heat generated by photothermal therapy had the possibility of promoting the release of DOX. In vitro cell experiment results showed that MBGC-xNd/SA had good osteogenic activity. Simultaneously, photothermal-chemical combination therapy had a more significant killing effect on MG-63 osteosarcoma cells, indicating a synergistic effect. Therefore, MBGC-xNd/SA, as a novel multifunctional bone repair material, exhibits a potential application in the postoperative treatment of osteosarcoma.