Brain-like neuromorphic computing is expected to overcome the bottleneck of traditional von Neumann computing architecture， achieving low power consumption and highly efficient information processing， thereby advancing artificial intelligence technology. Artificial synapses are key hardware for building neuromorphic systems， among which photoelectric synapses combine the advantages of electronics and photonics， offering multiple functions such as optical perception， information computation and storage. Emerging all-optically controlled photoelectric synapses， which allow nonvolatile increase and decrease in conductance by optical signals， can effectively prevent damage to the device microstructure caused by electrical signals， improving working stability， and endow synaptic devices with new functions. Oxide is the most widely used artificial synaptic material because of its ease of preparation and good compatibility with CMOS technology. This paper reviews the research progress of all-optically controlled （AOC） oxide synapses with long-term plasticity. The AOC synapses are discussed in terms of conductance modulation methods， including light wavelength and light power density modulation， focusing on device structure， material selection， and photoelectric response mechanism. Finally， we analyze the current challenges faced by all-optically controlled synapses.

neuromorphic computing;photoelectric synapses;all-optically controlled synapses;long-term plasticity;oxides