With the gradual popularization of electric vehicles, the performance testing of electric vehicle charging facilities has become an indispensable requirement, which is of great significance for the development and large-scale application of electric vehicles. This paper focuses on the research of electric vehicle interoperability. According to the principle of electric vehicle interoperability, the electric vehicle DC charging interoperability testing device is designed according to the latest national standards and specifications. According to the purpose of the interoperability testing project and the evaluation requirements and basis , testing each test item, and analyzing the test results. This study has important significance for the acceptance, on-site inspection, maintenance and operation and maintenance of electric vehicle charging facilities, and plays an important role in the development of electric vehicles.