According to the requirements of electronic equipment test, system openability and expansibility, an automatic test system based on PCI extensions for instrumentation (PXI) bus is developed. Hardware structures and software design methods of the system are described in detail. PXI embedded main control computer is used as the key part in the system and LabVIEW software is used as development environment. And the integrated design of the system is realized with standard interface and bus technology. The system has good man-machine interaction interface. It is stable and responsible in operation with high testing efficiency. And it is easy to be used and maintained.