A novel piezoelectric rotary actuator incorporating active inertia compensation was developed to suppress the significant backward motion inherent in small-inertia rotors， thereby achieving efficient and stable stick-slip motion. By implementing active inertia compensation and optimizing the timing of the driving voltage， the backward motion was effectively suppressed， leading to enhanced speed and smoothness of motion. The working principle of the actuator， based on the active inertia compensation method， was thoroughly analyzed. Structural analysis and simulations were conducted， and the theoretical feasibility of the active inertia compensation method was validated by comparing its effects with and without compensation. An experimental system for driving the small-inertia rotor was established， and comprehensive tests were performed to evaluate its output performance. Experimental results indicate that 79.77% of the rotor's backward angle can be suppressed using active inertia compensation. The minimum resolution of the piezoelectric rotary actuator with active inertia compensation is 1.12 μrad， and the maximum speed reaches 813.85 mrad/s. This method enables the high-efficiency and stable stick-slip motion of small-inertia rotor， thereby achieving high-performance output for piezoelectric rotary actuator. This has significant application potential in ultra-precision operations within complex workspaces， such as micro and nano-scale manipulations.