At present, the direct purchase of electricity by large users is mainly combined with a quota system. This has become an important way to promote new energy consumption. In order to explore a transparent and reliable direct power purchase method, relying on third-generation blockchain super ledger technology, a direct power purchase trading platform based on the alliance blockchain is built. First, the direct power purchase transaction and carbon rights management functions are automatically executed in the smart contract to ensure that the direct power purchase and carbon rights transaction paths are safe and checkable. Secondly, this paper introduces green certificate incentives in the direct power purchase market, and designs carbon emission rights trading to participate in the direct purchase market, and analyzes the models of different trading methods. Finally, transactions are run based on the designed trading platform to complete the whole process of "quotation-on-chain-block production". The results show that the participation of carbon rights in the direct purchase market can punish high-emission companies, guide emission reduction through market means, and provide new ideas for the construction of direct purchase transactions. This work is supported by the Key Special Fund of Intergovernmental Cooperation in International Science and Technology Innovation of National Key Research and Development Program of China (No. 2018YFE0122200).