The automatic damage detection system for a satellite solar array was firstly developed in China, and its detection theory, structure and design of detection system and the results of on-site trial were introduced. By using a unique lighting system, the image of the salar array was focused clearly onto a CCD sensor via an optical system, then the signals were multiamplified and A/D converted to store in a computer system. An imaging probe automatically scans the whole array and keeps the image clear through the control of a distance sensor. The customized system control and detection software were used to process every battery image, then testing results were shown on a table to offer the location of the damaged battery, damage types and damage degree etc. An on-site test shows that detection rate of the system is over 98.5% and detection speed is 20 batteries per minute, which meets the requirements of fast, accurate and automatic detection of the solar array.