Aiming at the problem that the performance of high precision fiber optic gyroscope with long coil degradation under vibration condition, the error mechanism of fiber optic gyroscope caused by mechanical environment is analyzed from the angles of optical path, structure and closed-loop control, and the system model of digital closed-loop control is established. According to the analysis and modeling results, a method to improve the vibration resistance of fiber optic gyroscope from the aspects of optical design, optical assembly technique, structure design and optimization of closed-loop control is proposed, and the gain parameters of optimized closed-loop control are designed to improve the response of the vibration environment. After optimized parameters, the anti-vibration performance of the fiber optic gyroscope has been greatly improved. The results also prove the correctness and effectiveness of the improved scheme, and achieve a breakthrough in the application of high precision fiber optic gyroscope in dynamic environment.