A precision micro-displacement system with displacement feedback was designed by high-precision capacitive sensor, which greatly corrects the nonlinearity of piezoelectric ceramics. A high-precision displacement detection circuit was designed to collect the capacitance of the capacitive sensor in real time and convert it into a digital signal to the DSP to form a closed loop of the displacement information. By combining with the PID closed-loop control strategy with feed forward compensation, the nonlinear characteristics of piezoelectric ceramics were corrected, and the precision displacement of micro-displacement system was realized. The results show that the capacitance resolution of the displacement detection circuit can reach 0.0001pF, and the positioning accuracy of micro-displacement system is better than 5nm, and the hysteresis error after correction is less than 1.0%.