In view of the problems that the miter gate of ship lock is in the complex water environment of low-speed, heavy-duty and overload operation for a long time, and the existing detection methods are low in automation, time-consuming and labor-consuming, and vulnerable to electromagnetic interference, a miter gate structural health monitoring system based on fiber Bragg grating sensing technology is proposed. Firstly, the sensing principle of fiber Bragg grating was described. Then, based on this principle, the structural health monitoring system of miter gate was constructed. The system could sense the strain changes of miter gate during operation, and realize the functions of real-time data display, abnormal data monitoring and early warning, historical data playback and so on. Finally, the data collected by the sensor was processed by median filter to improve the signal-to-noise ratio of the signal. The data are analyzed and compared to verify the repeatability and navigation relevance of the sensor data, which provides data support for the safe and stable work of the miter gate of the ship lock.