By using MCU as the controller

an integrated test system of aircraft avionics instrument which is based on synchro converters is designed to offline test the UUT on ground and to meet the fact that the auto-test equipment abroad is costly and the test equipment at home is performed special.The principles of aviation instrument test is described

meanwhile synchro transmitting circuit and receiving circuit is designed

enabling digital/synchro signal conversion.By using a digital I/O port and a relay panel to achieve measurement of diversity.Adopting method of dual-channel coupling system test precision is increased.The experimental result indicates that the test data is satisfied with CMM and test system is simple and effectively reduces the maintenance cost and improves the automation test level of aircraft equipment maintenance.