Abstract: With the ever demanding requirements of servo mechanisms for high precision and large slew rate in sophisticated detection and targeting systems, servo error sources such as gap, backlash and friction become limiting factors for the improvement of servo performance. The requirements of the cutting edge servo mechanisms for different electro-optical targeting systems on various platforms were investigated, which include missile, warship and aircraft applications. Major problems and challenges in designing and manufacturing precise servo mechanism were studied, and several key topics were put forward for the development of the precise servo mechanism, including error budget and dynamic analysis, design and manufacture, integrated mechanicalcontrol design method. Finally, future work is suggested for developing precise servo mechanism.