A composite material structure health monitoring system based on an embedded optical fiber grating comprises optical fiber grating sensors, an optical fiber, a composite material structure, a signal generation and demodulation system, a signal receiver, and a computer terminal. The signal generation and demodulation system generates a light signal and then sends the light signal to the optical fiber grating sensors. The optical fiber grating sensors are used to monitor the health of the composite material structure and return monitoring results to the signal generation and demodulation system through the optical fiber. The signal generation and demodulation system processes the monitoring results and sends the monitoring results to the signal receiver. The signal receiver receives the signal sent by the signal generation and demodulation system and transmits the signal to the computer terminal for data processing. The system is applicable to real-time monitoring of the forming process of the composite material structure and the ground test and air operation processes, and effectively provides high-precision strain data of the composite material structure.