With the widespread use of power electronics and nonlinear loads, the issue of harmonics in power systems has become increasingly severe, posing new challenges for energy metering. Harmonics can cause measurement errors in electronic energy meters, affecting the accuracy of energy metering and consequently impacting power billing and power system management adversely. To analyze the effects of harmonics on the measurement errors of electronic energy meters, this paper first constructs a model of the electronic energy meter. Through simulation analysis, the impact of various harmonic components on measurement errors is systematically studied. The results indicate that higher-order harmonics and those with larger amplitudes significantly increase the measurement errors of the meters, and the mechanism of how harmonics influence measurement errors is revealed. Based on these findings, this study proposes measures to enhance the harmonic interference resistance of energy meters, including the application of harmonic filters and the optimization of measurement algorithms. These improvements provide theoretical support for enhancing the accuracy of energy metering and practical references for the optimization of power system management.