JP+1]An automatic test system of high speed digital circuit based on VPX bus is designed in this paper to resolve maintenance ability of high speed digital circuit modules in the important strategic early warning radar and shipboard integrated radar. The system can test high speed digital circuit modules of multiple model radars. We establish the test system by researching multiple function test module, fibre-optical test module and universal backboard based on VPX bus, universal instruments are also used in the system. The system can provide ten fibre-optical channels which the highest transport frequency is 3.2 Gbps; sixteen GPIO signals which interrupt response time is less than 50 μs; fourteen Rocket IO signals which transport frequency is 2.5 Gbps; 4 *4Rapid IO signals which transport frequency is 3.125 Gbps. The research and test results show the system can resolve the test problem of high speed digital circuit modules based on VPX bus.