Since the DC charger of electric vehicle has been listed in the catalogue of measuring instruments under compulsory management by the State Administration of market supervision, its electric energy measurement performance has attracted more and more attention of the society. The actual use of DC charger has a wide range of temperature changes, which has a certain impact on the measurement performance of DC charger. In this paper, combined with the working principle of DC charging electromechanical energy measurement, the temperature is selected as the influence quantity, and the measurement accuracy of DC charging metering unit under different temperatures is measured by using the built temperature influence simulation test platform. This paper analyzes the rule of temperature influence of DC charger, and puts forward a temperature compensation model of metering unit of DC charger based on piecewise linear interpolation. The experimental results show that the accuracy of DC charging electrical energy measurement is improved obviously after temperature compensation, which verifies the accuracy and applicability of the piecewise linear interpolation compensation method.