In order to solve the problem of unstable initial segment tracking caused by unreasonable PID control parameter setting of radar servo system in a certain task. The mechanism of PID control parameters influencing radar servo system is analyzed in detail. The fault was accurately located. In this paper, an optimal design scheme of PID control parameters based on different target characteristics is proposed. Verification is carried out at short-range and long-distance points. The results show that all of them can meet the stable tracking target. It has certain guiding significance for the analysis, positioning and solution of the problem that the radar equipment is not compatible with different point rocket tracking parameters using a single PID control parameter.