The detection of weak ultraviolet light has garnered significant attention for critical applications such as missile tracking, flame warning, secure communication, and environmental monitoring. Avalanche photodetectors (APDs) are a major research direction for UV detection due to their lightweight, low power consumption, high quantum efficiency, and monolithic integration. In recent years, wide bandgap and ultra-wide bandgap semiconductor materials have been regarded as ideal materials for APD design due to their large bandgap, high electron saturation drift velocity, high breakdown field strength, high thermal conductivity, and good chemical stability. Among the reported materials, Ga₂O₃ stands out as a new material of interest due to its larger bandgap, higher breakdown field strength, higher Baliga's figure-of-merit, and shorter absorption cutoff edge. Ga₂O₃-based APDs, with advantages such as an ultra-wide bandgap, high breakdown electric field, controllable gain, and excellent thermal stability, exhibit high responsivity and internal gain, making them a hot topic in this field. This paper reviews the research progress of Ga₂O₃-based APDs, introducing the device structure, performance, development history, and research improvements of Ga₂O₃ APDs.