Abstract: Big data has great value. Applying big data in government can provide a reference to the government when making decisions. Besides, new applications will be created by applying big data so that the government can offer more and better services to the people. The establishment of government data sharing platform can lay the foundation for the application of big data in government in the future. But the government data sharing platform will bring many new security problems. In this paper, two security problems are studied. To manage the shared data securely, this paper proposes two-level management model. And to prevent the illegal secondary authorization of the shared data, this paper proposes sealed data mechanism that encrypts the shared data with the key associated the system hardware and software information.