Due to the excellent responsivity and high rejection ratio, Ga2O3-based solar-blind ultraviolet photodetectors are attracting more and more attention. The excellent material quality ensures great performance of photodetectors. In this review, we summarize recent advancements in growth methods of β-Ga2O3 bulk and thin films. Based on high-quality substrates and thin films, numerous state-of-art Ga2O3-based photodetectors have been reported in decades. Therefore, we collect some representative achievements in Ga2O3-based photodetectors, summarizing the development process of each type of structure. Furthermore, the advantages and disadvantages of different structures are also discussed to provide practical reference for researchers in this field. Additionally, inspired by the excellent performance of Ga2O3-based photodetectors, many research teams have also explored the applications based on solar-blind detection. We summarize three application fields, including imaging, light communication, and optical tracing, introducing some excellent works from different teams. Finally, we evaluate the outlook and remaining challenges in the future development of Ga2O3-based photodetectors.