The infrared seeker is an important subsystem of the shoulder mounted anti tank missile.Its main function is to lock the target and trace the target by manual operation of the target line motion.The paper adopts the rate gyro stabilized platform servo system,pitch and yaw of the double framed structure.Speed and position signals are provided by means of the rate gyro and angular position sensors installed in the frame,DSP and FPGA are used to build servo control circuit,using current,speed and position three-loop cascade closed-loop PID design control frame motor to realize target scanning and tracing.The scheme has strong tracking ability,high tracking precision,strong anti-interference ability,and easy to realize wide range scanning.