The current concentration-distribution model of government data opening not only has the chronic disease of over centralization, but also is difficult to ensure the overall effect of data distribution. In the process of data concentration, the data of multiple nodes is difficult to converge to the central node. In the process of data distribution, the data of central node is difficult to transfer to multiple nodes; In the process of data utilization, multiple nodes are difficult to interact with the central node. In view of this, it is necessary to change the current model of government data opening and seek a new technical support for it. Blockchain is an ideal technology to solve the problem of government data opening. Through four kinds of mechanisms including communication, storage, security, consensus, blockchain can ensure data flow, overcome single point of failure and bureaucratic organization limitations as well as promote the government to change its functions and enable multiple subjects to participate in data opening. However, when the single blockchain technology is applied to the opening of government data, it is still in danger of circumventing supervision, solidifying errors, cracking algorithms and re-centralization. There are problems that decentralization, security and scalability cannot be realized at the same time. Facing the technical demand of government data opening and the ternary paradox of blockchain technology, this paper introduces the concept of sovereign blockchain to explore the path of government data opening that can realize the compatibility of centralized sovereign state supervision and decentralized blockchain technology. There is a connection between sovereign blockchain and government data opening. Sovereign blockchain is a governance technology which can integrate institution and technology as well as has the function of distributing and concentrating. Relying on sovereign blockchain, we can build a government data opening model with government guidance and joint governance of nodes. Specifically, sovereign blockchain is composed of public blockchain, consortium blockchain and private blockchain. This structure helps to overcome the ternary paradox of single blockchain technology. Therefore, in the process of government data opening, we can choose appropriate blockchains according to different data types and application scenarios, and then create a sovereign blockchain of chain governance by building a public blockchain platform for the public, promoting the consortium blockchain governance of collaborative institutions, and strengthening the private blockchain isolation of functional departments. In government data opening based on sovereign blockchain, the public blockchain with distributed and open characteristics is conducive to the sharing of underlying data and the access of the consortium blockchain. The consortium blockchain can not only build a data sharing platform between government departments by limiting the participating nodes to a limited range, but also establish a legal chain by embedding the public blockchain, and place the blockchain under the sovereignty framework to ensure national supervision. The data on the public blockchain will be tested by the consortium blockchain, in which sensitive data will be retained on the private blockchain, and other data will be transmitted to the public from the public blockchain. The private blockchain is used to provide a secure storage environment for the diverted sensitive data.