Small molecule prodrug self-assembly nano-release system is a new strategy that uses small molecule prodrug (small molecule prodrugs) as a drug carrier to form nanoparticles through self-assembly, so as to achieve accurate diagnosis and treatment of tumor cells. Small molecule prodrug is a chemically modified drug that can release the original drug under specific conditions. Small-molecule prodrug self-assembly nanoscale release system is highly stable, biocompatible, tunable, and functional, and can be used to enhance various antitumor methods such as phototherapy, chemotherapy, and immunotherapy.