With the popularity of the Internet and mobile terminals, the digital trade industry is becoming a major economic growth point. Digital trade and cross-border e-commerce are the upgrading and iteration of traditional international trade under the new situation of current technological development. This paper starts from the problem of barriers in digital trade industry, analyzes the significance and advantages of blockchain technology for the construction of digital trade industry value chain, puts forward the proposal of reshaping the ecological value chain with blockchain-based digital trade platform, and then analyzes the key elements in the new type of platform, the flow of value, the platform architecture, and designs the basic scheme of the platform's flow of value, and finally puts forward the most promising digital trade value chain framework in terms of the cost and the blockchain. Finally, the most promising digital trade value chain framework is proposed from the perspective of cost and blockchain.