As the actuator of micropositioning system, the piezoelectric ceramic can achieve nanometerscale displacement accuracy. In view of the large capacitive load characteristics of displacementdriven piezoelectric ceramics, a highprecision, highcurrent dynamic drive power supply is designed based on PA92. The stability of power supply is improved by the means of the capacitor lead feedback, isolation resistor combined with feedback and phase compensation. The analysis results show that the power supply can be effectively applied to the nanoscale positioning system, and has good dynamic performance under large capacitive load, and the output voltage accuracy can reach 05 mV.