The accuracy of the electronic voltage transformer is the guarantee of safe and stable operation of power system and accurate measurement of power. Because the technology is not yet mature, some problems arise during the operation, among which the accuracy problem is the main problem. Currently, the study on the analysis of the factors which affect the accuracy of electronic instrument transformer is very few. For this reason, the error model of electronic voltage transformer based on resistance divider is created in this paper, and the impedance matching between the transformer and small analog signal power meter is analyzed. On this basis, the measures to reduce the transformer error are proposed, and it has a certain significance to improve the accuracy of electronic voltage transformer.