Efficient testing and fault location of aircraft onboard equipment are achieved through real-time collection and analysis of physical signals (such as voltage, current, frequency, vibration, etc.) of onboard equipment. And it is carried out in combination with intelligent diagnostic algorithms. The test system adopts an automatic query method to find the test instruments in the system that meet the requirements under test. Output the signal by analyzing the attributes of the signal required by the test program. The signal-oriented aircraft automatic test system based on the ATML standard adopts the test signal modeling technology and the automatic mapping technology between signals and test resources. The sharing of test programs among aircraft automatic test systems is achieved through the automatic test software of the ATML standard; Through the analysis and sorting out of the test requirements of the test unit; Write test programs that meet the test requirements to control various instrument resources in the test system to complete the test verification of the aircraft's on-board equipment. Pass verification; This system has significantly improved both the fault detection rate and the detection efficiency compared with the traditional methods.