Abstract:An automatic test system based on virtual instrument is designed to solve the problems of complex operation and high cost of the current military distribution equipment testing system. The proposal of the system can improve the advanced nature, generality, standardization and automation of the system unit test, and can complete the automatic test of distribution equipment, the function test of the device, the resistance test, the delay time test. And monitoring the reliability of relay contact closing state in the process of vibration testing. The hardware of the system is mainly composed of a computer based on PXI bus and a variety of NI boards, including PXI-2737 matrix switch board, PXI-4072 digital multimeter board and PXI-7811r digital I / O board. In the software part, LabVIEW is used as the software development platform of the automatic test system, which makes the system more extensible and maintainable. The system realizes the functions of real-time acquisition, display and automatic storage of the test data, and records the test data of the distribution apparatus under test. The practical application system meets the engineering requirements of safety and reliability, convenient operation, low cost and high efficiency, and meets the requirements of modern testing.