Abstract: The second-order proximate model on closed-loop system of Micromachined Capacitive Accelerometer is set up. Influence of the gain and bandwidth of servo-circuit on the dynamic behavior of closed-loop system is analyzed. The method to compensate dynamic performance of servo-system by adjusting the parameters of servo-circuit is put forward. The computational methods of start-up response time and output error of servo-system are given in different inputs.