With their unique physicochemical properties including excellent stability and biocompatibility, large specific surface area, and easy surface modification, gold nanoparticles (AuNPs) can be used as delivery vectors for drugs, genes, proteins, etc. In addition, AuNPs have excellent photothermal effects and radiosensitization characteristics, and therefore can be widely applied in the photothermal therapy and radiotherapy of cancers. This article reviews the construction, cellular uptake, and drug release of AuNPs drug-delivery systems and their applications in the treatment of tumors.