As the mechanic resonance of Piezoelectric Fast Steering Mirror (PFSM) degrades the correction width of an adaptive optics servo loop, this paper explores the method to improve the performance of the fast steering mirror in high-speed applications. On the basis of the dynamic model and measured data of the PFSM, a multi-order two-second digital filter was embedded in the Field Programmable Gate Array (FPGA) of the high-voltage driver. The digital filter could suppress or compensate the resonance point and the anti-resonance point at the same time. As a whole with the PFSM, the optimized frequency response of the high-voltage driver flattens the magnitude response,avoids undesired resonance behavior and improves the control bandwidth. As compared with that of traditional high-voltage drivers, experimental results with the proposed high-voltage driver show that the control bandwidth of the system is effectively improved from 56 Hz to 80 Hz at the same overshot, and also the error rejection at low frequency is enhanced. The high bandwidth high-voltage driver with a plant characteristic compensator is more attractive to drive the PFSM in high-speed applications.