The method of improving the design bandwidth of hemispherical resonator gyro (HRG) is studied to meet the needs of engineering application of a platform inertial system.The top head gain and transfer function of the gyro have been obtained by the experimental method, the proportionalintegraldifferential controller correction method is used to design the control loop,then the pole zero transfer function is determined through the simulation software. The frequency characteristic curve drawn by the simulation results verifies the express and stability of the control circuit.The bandwidth of the optimized HRG has improved to 20 Hz and the output noise has improved to less than 3 mV,and it satisfies the application of the inertial navigation system.The practical application has demonstrated the effectiveness and reasonableness of the design.