The steering gear is the key part of the missile control system, and the performance of its internal power amplifier components affects the flight state of the missile. However, in the performance detection process of the steering gear system with SA03 power amplifier as the core, the traditional manual detection method is not only low efficiency, complex operation, especially in the manual plug and switch resistance to adjust the saturation voltage, not only time-consuming and easy to cause damage to the circuit board. In order to meet the requirements of automatic testing of steering gear amplifier in batch performance inspection process, based on Lab Windows/CVI platform, this paper designed an automatic testing system for performance parameters of steering gear amplifier, which can simultaneously evaluate and test the performance of four steering gear amplifiers and their related drive and control circuits. The system can provide power supply and control signal input for the product to be tested at the same time, the data acquisition, processing, interpretation and electronic storage of test indicators, the detection of saturation voltage using programmable resistance continuous adjustment to solve the existing problems. The application results show that the system is simple to operate and has good test effect.