Abstract: The handover test is required after the construction of high-voltage electrical installation project. Among them, there are many items and high requirements for voltage transformer test. Its qualification is one of the key factors for system power transmission and operation. The discrete test method is mostly used on site, which has complicated test and many unsafe risk factors. It is urgent to improve its test equipment technology in combination with the requirements of test procedures. This paper explores the application status of electronic power products at the present stage, and puts forward bold innovations in the test equipment technology and test process of voltage transformer, This paper studies a comprehensive test device of voltage transformer, applies and analyzes the technology of realizing on-line test and comprehensive test of voltage transformer.