The invention provides a security evaluation method and device for DC charging equipment power grid accessing. Firstly the power grid operation parameters before and after the DC charging equipment isaccessed to the power grid are obtained and then the security of the DC charging equipment accessing to the power grid is determined according to the evaluation indexes in a pre-constructed securityevaluation index evaluation system, wherein the security evaluation index evaluation system comprises a target layer, a criterion layer and an index layer, and the evaluation indexes in the index layer are determined through the power grid operation parameters. The utilization rate of the DC charging equipment is enhanced and the DC charging equipment is ensured to be securely accessed to the power grid. The specific security evaluation indexes for determining the influence of DC charging equipment on accessing the power grid are provided from two aspects of DC charging equipment affecting thesecurity of the power grid and the power grid affecting the security of DC charging equipment, all-round consideration provides a reference basis for the secure access of the DC charging facilities to the power grid, and the principle is concise and the method is simple and has good operability and practicability.