The invention provides a direct-current charging system of an electric automobile. The direct-current charging system of the electric automobile comprises a centralized converter system and a distributed charging pile terminals, wherein the centralized converter system is arranged in a transformer substation, an input power source is connected to the input end of the centralized converter system,and the output end of the centralized type converter system is connected with the distributed charging pile terminals. The centralized converter system comprises a power module, a high-frequency transformer and a first AC/DC conversion unit. According to the electric vehicle direct-current charging system designed by the invention, the centralized converter system is arranged in the transformer substation, so that the occupied areas of the charging piles are reduced, and reasonable utilization of resources is realized. The centralized converter system converts current, so that a converter device in a single charging pile is avoided, and the cost of the charging system is greatly reduced. The charging piles are uniformly connected to the centralized converter system in a unified mode, so that coordination control of all charging piles is achieved.