Fiber optic gyroscope, as a new type of all solid state gyroscope, has the advantages of fast start-up, wide measurement range, and high reliability. Among them, the U-F3X90 fiber optic gyroscope IMU (inertial measurement unit) is designed for the needs of medium and low precision application backgrounds, using three-axis shared technology, with low cost and stable performance; Structurally, it adopts integrated packaging of light path and circuit, with a simple structure and convenient installation. It can be applied to navigation guidance, attitude measurement and control systems of small missiles and guided bombs.