Aiming at the problems with low-safety and poor-autonomy existing in the large-scale electric vehicles(EV) during charging transaction, the EV charging transaction model based on blockchain technology is proposed. Under the competition mechanism of "multi-seller and multi-buyer" in power market, the commodity attributes of electricity are restored and the right of users to negotiate pricing is opened by utilizing the characteristics of blockchain technology for decentralization and high security. Firstly, EV charging transaction framework based on the blockchain architecture is established. And then, based on the similar network topology between the blockchain platform and the electricity market, EV charging transaction model under the blockchain architecture is established. Finally, comparatively analyze the charging schemes that meet the requirements of electric vehicle aggregators in the traditional electricity market and the electricity trading market under the blockchain platform. The results of calculation examples prove that the model established can meet the individual claims of electric vehicle aggregators, increase the revenue of new energy power plants, reduce carbon emissions, and provide a new idea for the electric vehicle charging trading market.