Professional equipment is lacking when it comes to intelligent terminal testing in the power industry. The existing test system has complex structure, complicated configuration, heavy wiring and changing operation, complex data processing and multiple error sources. All of these restricts testing efficiency and quality. To overcome the disadvantages of the existing test system, an intelligent terminal automatic tester is developed. This can realize the closed-loop automatic test of an intelligent terminal, simplify the test system, and improve testing ability and efficiency. Through the standardization of interface and configuration, all wiring and configuration are completed before the start of the test, so as to realize zero line connection and change operation in the test. Using automatic circuit switching technology, the test circuit is pre-designed and the automatic circuit switching and construction are carried out according to the requirements of different projects in the test, so as to realize the automatic test and zero line change operation. Through transparent display technology of the test process, the real-time processing and display of the test results are realized. This is convenient for the analysis and judgment of the results. By test verification and engineering application, it is shown that the accuracy and anti-interference ability of the intelligent terminal automatic tester meet the standard requirements. The automatic test ability and efficiency are significantly improved compared with traditional methods, meeting the application requirements. This work is supported by the National Natural Science Foundation of China (No. U1804252).