At the beginning of the 21st century, β-Ga2O3, an ultra-wide bandgap semiconductor, was researched initially in Japan. β-Ga2O3 wafers with different orientations were prepared by Tohoku University using floating zone technique. High-quality homoepitaxial wafers was obtained by Kyoto University which was engaged in β-Ga2O3 epitaxy research. Based on this substrate, the first Ga2O3-based MESFET device was successfully constructed by Japan National Institute of Information and Communications Technology in 2012. This work demonstrated the great potential of β-Ga2O3 in power devices and opened a new era of β-Ga2O3 research. Since then, β-Ga2O3 single crystals, epi-wafers and devices have attracted a lot of research institutions’ attention. Recent years, with the technological progress, the upper limit of breakdown voltage of β-Ga2O3 power devices was repeatedly refreshed. The time line of the development of β-Ga2O3 single crystal, epi-wafers, devices and the research status of power devices are summarized and analyzed in this article. This paper points out the existing problems and possible solutions in the application of β-Ga2O3, and looks forward to its future development, and provides a reference for the future technological development of β-Ga2O3.