This paper introduces a gyro control system with the quadrature control circuit. The control system realizes the automatic decoupling of driving mode and sensing mode. The quadrature control circuit eliminates the quadrature signal in the sensitive mode by applying a voltage to the quadrature control electrode. The time needed to adjust the voltage can be changed by adjusting the parameters of the controller. The control system is realized by a digital circuit. The feasibility of the design is verified by the test.