A piezoelectric inertial rotary actuator with variable normal pressures and asymmetric grippers was designed, which driven by a asymmetric clamping piezoelectric bimorph vibrator. The motion mechanism of the piezoelectric inertial rotary actuator was analyzed, then a simulation model of the asymmetric clamping piezoelectric bimorph vibrator was established and an experimental platform was built. By both the ANSYS simulation analysis and comparison experiment, the transient response of symmetric square wave of this asymmetric clamping piezoelectric bimorph vibrator was demonstrated. The results show the asymmetric clamping piezoelectric bimorph vibrator has good inertial impact performance under a symmetric square wave. The further variable normal pressure tests on different angles and stimulation frequencies for the piezoelectric inertial rotary actuator illustrate that the return length in each step is apparently reduced when the clamping difference is 4 mm, the stimulating voltage is 30 V, the stimulation frequency is 5 Hz and the angle between the piezoelectric vibrator and the surface is 50°, by which the piezoelectric inertial rotary actuator implements a stable unidirectional rotation.