The national“Twelve Five”puts forward that industrialization and urbanization have deeply developed in synchronism to advance agricultural modernization. In order to promote simultaneous development of industrialization, urbanization and agricultural modernization, based on the brief analysis of the concepts, this paper analyzes internal mechanisms with simultaneous development and relationships between any two about industrialization, urbanization and agricultural modernization through the function model, the cube model, and the mutual relation and the graphic methods. The policy and recommendations have been put forward including advocating low- carbon development, taking a new road to industrialization; accelerating the development of small towns, advancing rural urbanization; strengthening the position of agricultural base, improving the agricultural comprehensive production capacity