This article introduces a automatic test system for flight control system. Flight control system ownes powerful capabilities, complex structures and intercommunions among other systems in airplane. The test procedure of flight control system is very complicated and has some special characteristics such as on-line test, close-loop test and dynamic test. According to these circumstances, the author designed a automatic test equipment based on VXI bus that realized dynamic test for flight control system. We adopted flight simulation technology to construct flight environment in order to meet the test requirements. Through reasonable design of switch arrays, we solved the confliction problem between many test points and limited instrument resources. We also made use of standard test unit adapter to enhance the universal and expanded ability of test system. We have successfully used this technology to the test of flight control system of airplane.