Airborne electro-optical stable platform can isolate movement and vibration of the airframe, stabilizes the optic axis of the photoelectic detector, realize the observation and tracking for the object. It has comprehensive application value in army and cicil field. Most of present airborne platforms are analogic control system, digital control system can improve the system general performance, digital control is the development direction of platform systems. In view of the requirements of isolating disturbances and stabilizing optical axis of high-precision photoelectric guidance system, a three-axis stabilized platform system centering on the rate gyro was designed. The disturbance-isolation theory of the stabilized platform was analyzed and the control structure including multiple closed-loops was designed. At last a controller of the servo system based on TMS320F2812 DSP has been designed. Experiment results meet the technical index and precision requirement, and illustrate the practicability and effectiveness of the scheme.