In order to complete the task of off-line rapid detection and maintenance for the antenna servo system of a certain type of equipment search radar, a set of detection and diagnosis system is developed. The system simulates the generation of external input signals and various control signals, responds to the output control signals by simulating the actuator of the antenna servo system through the simulation load, reproduces the working process of the antenna servo system controlling the erecting, withdrawing and rotating of the search radar antenna in an off-line state, automatically judges the test results, and gives fault codes to guide maintenance. The application results show that the system has the characteristics of simple operation, high degree of intelligence, fast and efficient detection and diagnosis, and can complete the required test items, and the test results meet the technical requirements.