Abstract: In the new development environment, think-tank as an important component to support the development of all sectors of society, is necessary to enhance service level and service quality in open innovation environment. Based on the impact of open innovation environment on the development of new think-tank, this paper summarized the development trend of current knowledge service from three aspects of service orientation, service content, service system, and put forward the basic problems to build new think-tank service mode in open innovation environment from service framework, system and method. Finally, it proposed the development strategy of knowledge service mode for new think-tank from environment, mechanism, service and technology, so as to promote the improvement of knowledge service level of library think-tank under the new situation.