It introduces a vibrating-string gyro with electromagnetic driving frequency detection. In order to realize the amplitude stabilizing resonance of the vibrating-string gyro, the dynamic and electrical characteristics of the vibrating-string gyro driving mode are analyzed. The closed-loop drive system based on the phase negative feedback was designed according to the characteristics, and its Simulink system model was established, the frequency-locked amplitude stabilization performance of the drive system was analyzed when the natural frequency of the drive mode was deviated. The device-level circuit implementation and simulation of the closed-loop drive system were carried out. The results show that the gyro’s stable amplitude start-up time is about 1.5 s, and the frequency jitter after stabilization is less than 0.020 6 Hz. Finally, the closed-loop drive circuit was fabricated and the drive test was carried out, the test results were consistent with the simulation results, which verified that the closed-loop drive circuit was able to achieve the control requirements of gyro frequency tracking and stable amplitude.