The Solar-blind UV detection has wide application scenarios and unique market values in the civil and military fields, such as space security communication, ozone hole detection, missile attack warning and so on. Gallium oxide (Ga₂O₃) has an extremely wide band gap (4.4-5.3 eV), almost covering the entire solar-blind UV region, and is considered as one of the most promising materials for the preparation of solar-blind UV photodetectors. Compared with single crystal or epitaxy materials, amorphous gallium oxide (a-Ga₂O₃) has a lower deposition temperature, a relatively simple preparation process, and a much wider range of applicable substrates. Therefore, it has become a new research hot spot in the field of the Ga₂O₃ solar-blind UV detection in most recent years. In this paper, the basic characteristics and most common preparation methods of a-Ga₂O₃ are introduced firstly, and then the research progress and present situations of the a-Ga₂O₃-based solar-blind UV photodetector are introduced in details from the perspective of device structures. At present, a-Ga₂O₃ based solar-blind UV photodetectors are mainly divided into MSM, junction, TFT and array types. By the optimization of device structures, the photodetection performance has been significantly improved. MSM device is the most widely used because of its simple structure and high responsivity. By constructing Schottky junction or heterojunction, the junction-type devices own the characteristics of fast response speed, low dark current, and self-power supply. TFT devices can suppress the dark current, amplify the gain and improve the recovery speed by applying gate voltage. Array-type devices can be used for large-area imaging. Finally, the future development trends of the a-Ga₂O₃ solar-blind UV photodetector are summarized.