Abstract: The servo system of the self-propelled anti-aircraft artillery has the possibility of failures. While working in the emergency state, it has the problems of slow reaction, low precision and large error for lead. To solve these problems, the dynamic cursor circuit was proposed to use for producing the video frequency with a dynamic cursor. Thus, the target data and the lead of artillery could be calculated in real time, so as to control the position of the dynamic cursor. The video frequency signal was shown on the display screen and projected to the reticle surface of the sight lens, enabling the dynamic cursor in the field of view. Therefore, it could guide the user to aim manually and to slew the artillery to the lead position rapidly while working in the emergency state. The use of the dynamic cursor in the sight lens could reduce the operational difficulty and improve the slew rate, facilitating to grasp the fighting chance and increase the probability of hitting. This device was tested with a type of self-propelled anti-aircraft artillery. The results show that it fulfills its intended functions and can attain the predetermined effect.