Due to the fine micro/nanometer resolution, fast response, and large mechanical force, piezoelectric-driven stage has been employed in high-precision positioning system. However, piezoelectric actuator induces the problems of nonlinear hysteresis, creep, and time-varying uncertainties. It is hard to achieve satisfactory performance using traditional linear control method. Thus, a generalized extended state observer (GESO) based enhanced active disturbance reject control (ADRC) is developed to improve the system performance in this paper. The proposed GESO observer could estimate total time varying disturbance and compensate it in the feed-forward channel. Experimental results are given to show the effectiveness of the proposed control scheme.