The wide distributed energy has been the focus of power market. However,the traditional power trading platform cannot meet the high efficiency,flexibility,security and reliability requirements of the large-scale distributed energy transactions. To resolve the contradiction between high information processing complexity and the requirements of safe and fast transactions,a distributed energy trading system architecture and its overall design scheme based on cloud-edge collaboration and block chain is proposed. First of all,the system architecture of cloud computing and edge computing collaboration combined with two-layer blockchain is designed to realize transaction decentralization by using blockchain technology. It improves the autonomy and efficiency of transactions,and enhancs the processing capacity of massive data and the expansion capacity of the transaction system by using cloud edge collaboration. Then,a distributed energy trading mechanism is designed based on two-way bidding and prediction compensation, and the core consensus algorithm of blockchain is further analyzed. The delegated proof of stake (DPoS) is used as a highly efficient and reliable consensus algorithm of the trading system to realize efficient and reliable transactions of large-scale distributed energy,thus promoting distributed energy to participate in power grid regulation and improving the stable operation level of power grid. Finally,the applicability and superiority of the proposed system to large-scale distributed energy trading are verified by application example.