In view of the complexity of information dissemination in agriculture and the uncertainty of farmers’ demand for scientific and technological information, this paper makes a comprehensive and accurate analysis for the dissemination network of scientific and technological information of agriculture based on complex network technology. Firstly, this paper researches the characteristics of the peak degree distribution, average path length and clustering coefficient of a complex network established by the agricultural information dissemination network. Through the research on the three basic characteristics, this paper confirms that the agriculture information dissemination network has the characteristics of scale-free network and small-world network. The method of node research is analyzed by using a complex network. That is that this paper makes a comprehensive analysis for the information propagation speed, scope, analysis and application of dissemination network of agricultural scientific and technological information from degree centrality, betweenness centrality and relationship strength theory. The research results show that the degree centrality can accelerate the information dissemination and be conducive to the accuracy of the information; the betweenness centrality can quickly expand the information dissemination and accurately grasp the degree of control for information resources; the relationship strength theory can reduce the cost of information dissemination and improve the degree of information adoption. This conclusion proves that the application of the analysis method of complex network can effectively improve the speed and quality of agricultural information dissemination network and better serve the agricultural production and farmers’ life.