Abstract: From equivalent electronic model of piezoelectric ceramic and driving signals waveform, reason which causes back rotation on metal ball of ball base microactuator in the inertia-friction driving process is analyzed, a rotate velocity model and displacement model of metal ball are set up in this paper. Designing a quickly discharging circuit to accelerate discharging of piezoelectric ceramic is put forward to decrease the back rotate displacement and vibration of metal ball, and then to enhance characteristics of microactuator. Finally, using three piezoelectric tubes as micro driving elements, a microactuator based on inertia-friction driving principle was designed and then experimented. Experimental data prove back rotation exists on the ball and the models are reasonable.