Based on the challenges and current research status of smart information service in libraries under big data environment, this paper first discusses design ideas of smart information service system in libraries from a data-driven perspective. Secondly, based on the theory of information ecology chain，supported and guided by the business process of the library, it constructs a data-driven smart information service system in libraries , which mainly includes infrastructure layer, data resources layer and service application layer. Besides, this paper has a detailed discussion about the functions and features of each layer. This system is able to integrate the library's infrastructure, data resources, service and users. It can also provide development strategies for big data-driven smart information service in libraries, improve the utilization of the library's data resources, reconstruct the business process of library's intelligent information service, as well as realize the construction and development of library's intelligent information service under the big data environment.