There are many shortcomings in the traditional treatment of cancer, which prompts the research direction of tumor treatment to turn to nanotechnology. Nanotechnology can be utilized to develop and prepare nano-sized materials for disease treatment, diagnosis, and imaging agents. Graphene quantum dots, as a carbon-based nanomaterial with both graphene sheet structure and quantum dot luminescence properties, have the advantages of low biological toxicity, high fluorescence quantum generation rate, stable photoluminescence and superior biocompatibility. They are widely applied in different fields such as catalysis, sensing, bioimaging, medical diagnosis and tumor treatment. Therefore, they become a research hotspot in biomedical materials. This article mainly reviews the research progress of graphene quantum dots in drug delivery, photodynamic therapy, photothermal therapy, fluorescence imaging and tracing in combination with their preparation, properties and applications.