Abstract: The metal oxide surge arrester (MOSA) leakage current live test is one of the most frequent live tests carried out by the electrical equipment operation and maintenance company, the traditional live test method has shortcomings such as the second voltage terminal positioning is time-consuming and laborious, and lifting the signal line is prone to accidentally trip equipment, etc. The MOSAs leakage current live test voltage extraction intelligent terminal introduced in the paper is based on the actual needs of the daily work, to make up for the many shortcomings of the traditional live test methods, with the improvement of the efficiency in locating the voltage terminals, to avoid choosing the wrong terminals or picking up the signal process of accidents caused by the bad touch, easy to operate, strong insulation performance, low manufacturing costs,and high economic efficiency features. After installing the device by accurately positioning the second voltage terminals, each test doesn’t need to locate terminals again. The staff could use the terminals on the terminal panel directly, enabling single-person operation.