The key design and implementation methods of Miniature 3-axial Fiber Optic Rate Sensor are described in detail. Based on plenty of theoretical analysis and experimental validation, effective measures and key technology on optical components, fiber coil technics, assembly methods, control circuits and structure solidity are adopt and summarized. Finally, its main engineering performance is tested and listed detailedly. From experimental results and engineering practice, we can conclude that Miniature 3-axial Fiber Optic Rate Sensor has the performance of high reliability, radiation resistance, low air pressure resistance, temperature resistance and high reliability, and can be widely used in some special and professional fields. More importantly, it greatly promotes the development of fiber optic sensing and inertial technology application of China.