The construction of trusted data space is an important part of data governance in our country. The library's participation in the construction of trusted data space has a solid foundation of public logic, service logic and system logic, which can give full play to the values of data resources, data management, knowledge service and trust construction. In the construction practice, libraries and industries need to play an active role, find the cutting position in the national policy, and find the best model in the practice exploration. The successful construction of European digital library and Civic Switchboard provides reference for the construction of trusted data space in Chinese libraries.