Abstract: Hydropower is an important part of clean energy, and the stable operation of its generating units is crucial to the security of the power system. As an advanced monitoring method, vibration sensing technology plays an important role in fault diagnosis of hydropower units. This paper analyzes the basic principles of vibration sensing technology and its application in fault diagnosis of hydropower units, and discusses its key role in monitoring equipment operating status, identifying fault characteristics and optimizing maintenance strategies. Combined with practical application scenarios, the advantages of vibration sensing technology in improving equipment reliability, reducing maintenance costs and extending equipment life are elaborated. The results show that vibration sensing technology can effectively improve the operating efficiency and safety of hydropower units and provide technical support for the high-quality development of the power industry.