Aiming at the shortcomings of the current piezoelectric micro-displacement control system, such as model nonlinearity, complex system or instability, a micro - displacement linear control system based on piezoelectric hysteresis symmetry and one-way single-loop cycle is proposed. Firstly, two piezoelectric displacement actuators with the same performance are located at the symmetric point of the loop by using the axisymmetric property between the positive and inverse hysteresis curves, and their hysteresis nonlinear effects cancel each other, so that the total displacement output has a linear relationship with the input drive voltage. Secondly, in order to avoid the complexity and instability caused by the appearance of the secondary loop and ensure the output precision of the piezoelectric system, only one determined main loop is used in the displacement adjustment process, and the two displacement actuators are adjusted according to the one-way counterclockwise direction of this main circuit. According to the proposed model and algorithm, experimental verification is carried out, and the error is analyzed and compensated. The results show that the displacement output precision of the model reaches nm level, the maximum error is 15nm, and the average error is about 0nm. At the same time, the model has the advantages of simple structure, small amount of calculation, easy implementation, and linear relationship between input and output.