The report of the Twentieth National Congress proposed to “accelerate the construction of agricultural power” and “implemented the strategy of innovation-driven develop”. In the new era and new journey，We should accelerate the construction of agricultural power by continue to optimize the policy system for agricultural science and technology innovation. Based on the policy diffusion theory，This article applies R language text mining technology, analyzes the characteristics of policy diffusion. This article finds that China’s agricultural and rural science & technology innovation policies show a top-down diffusion pattern, the implementation intensity and response speed of subordinate government to superior policy are increasing and the policy focus have high similarity. The policy theme diffusion show obvious time characteristics, the policy content continuously refine, the efficiency of policy transmission continues to increase, but the policy interaction is less.