The design of the controller is one of the cores of the precision tracking algorithm. In order to meet the requirements of tracking precision, a complex control system based on the target state estimation is constructed. The ideal position loop model is constructed based on the characteristics of the system frequency. The influence of the mid-band height and width on the dynamic performance of the system is also analyzed. On the premise of satisfying a certain phase angle margin, the approximate formula of resonance peak [Mr] and mid-band width H are deduced, and the parameters of lag-lead controller are determined. The bilinear transformation is used to achieve the digitalization of the controller, which is convenient for the simplification of the engineering operation. It is verified by practical systems, and better effect is got.