If the feedback signals lose or abnormal in the loop, it may causing whole system abnormal of work and cause system damage or people injured. Aiming at the proposed problem, introduce a security control strategy design realization of high accuracy triple-loop servo system. Taking the servo system of some type of electro-optical tracking device as an example, proposes an introduction of the system, an analysis of security control strategies and the principle chart. This device has been applied to certain type of electro-optical tracking device, and the practice results show that the strategies can improve the reliability and control security of the servo system effectively.