Bone cements have been used in the clinical setting to fill bone defects resulting from bone tumors. However, traditional bone cements do not have the function to kill tumor cells. This study develops a new type of tricalcium silicate (CS) based functional bone cement with excellent photothermal performance for the minimally invasive therapy of bone defects as well as bone tumors. Graphene oxide (GO) was introduced into the CS cement by co-precipitation of CS particles with GO nanosheets to form a CS/GO composite material based on charge interactions between the CS and GO. The incorporation of GO enhanced the self-setting properties of CS and endowed the cement with excellent photothermal performance with the irradiation of near-infrared light. Besides this, the temperature of the composite cement could be regulated by adjusting the laser power and the GO content, where the rising temperature significantly inhibited the growth of subcutaneous tumor tissue in vivo. In addition, the hydration process and development of the early compressive strength of the composite cement could be modulated based on its photothermal performance. Moreover, the CS/GO composite cement retained the bioactivity of CS to promote cell proliferation and the alkaline phosphate activity of MC3T3-E1. Therefore, the CS/GO composite cement holds great promise as a new type of functional bone cement with photothermal performance for bone tumor therapy and bone defect repair.