Hydrogen energy, recognized as a clean and renewable source, has progressed rapidly in recent years under the global initiative for energy conservation and emission reduction. Optical sensing has also advanced swiftly, offering high precision, fast response, low power consumption, and no arc generation issues. It has been widely applied in remote sensing, bio-detection, agriculture, and environmental monitoring. Our study focuses on optical hydrogen sensing technology. We begin by briefly elucidating the principal features of optical hydrogen sensing compared to other hydrogen sensing technologies. We then review the different mechanisms and device types within existing optical hydrogen sensing technologies. Subsequently, we analyze and discuss the developmental history, current research status, and prospects of various optical hydrogen sensing types, including spectroscopy, palladium-hydrogen phase change, optical fiber, and photo-electric composite types, as well as the challenges they face. We also explore the application requirements for different scenarios. Finally, we compare the main technical performance indicators of mainstream optical hydrogen sensors that have been reported and provide perspectives on the research directions and future development of optical hydrogen sensing technologies.