According to the actual application status of direct-current charging in the field of electric vehicles in China. This paper emphasizes the importance and necessity of precise measurement of direct-current power. In order to reduce the adverse impact on the metering accuracy of the charging pile when the shunts are supplied with large current for a long time. Therefore, a method to optimize and improve the measurement accuracy is proposed. By studying the accuracy of DC charging pile measurement and the source of loss, the structure of the measurement connection device is improved and the corresponding measurement module is designed. In addition, A high-precision digital metering device for direct-current charging piles is developed to ensure accurate measurement of the charging current and monitor the charging safety by replacing the shunt with a high-precision digital current sensor. This conclusion can help promote the healthy, rapid and sustainable development of electric vehicles.