Due to the lack of corresponding test equipment, key technologies and test procedures, the field accuracy calibration test is not fully carried out for the DC electronic voltage transformer (DCEVT) which is widely used in the power grid at present. Under this circumstance, its theory, transmission mechanism and error source are completely analyzed firstly. Then, for the fact that there is no synchronous signal port accessing in the converter station merging unit. A scheme of synchronous field calibration in different places is proposed, and the development of high accuracy field calibration system and uncertainty analysis is carried out. The proposed method is verified in Yongfu DC project, which provides a reference for the field calibration of DC electronic voltage transformer in converter station in China.