The research progress of optical hydrogen sensing technology based on surface plasmon (SP) is summarized, and two measurement methods based on SP, namely localized surface plasmon resonance (LSPR) and surface plasmon resonance (SPR), and then the measurement method, sensing structure and sensing characteristics of the sensor based on these two principles are expounded. In addition, various existing optical hydrogen sensors are reviewed, and their advantages and disadvantages are introduced. Finally, we emphasize the development direction and important challenges of SP-based optical hydrogen sensors in the future, such as special materials with specificity and stability, new nanostructures that are constantly developed and applied, and multi-point sensors that can meet future needs.