On the basis of giving an overview of efficiency research on transformation of land from fragmentation to scale economy, by using the concept of coupling in physics, this paper expounds the behavior basis of transfer of surplus rural labor forces in China and transformation of land from fragmentation to scaling up, and analyzes behaviors of all parties and equilibrium outcomes in the three stages concerning the transformation of agricultural land from fragmentation to scaling up as follows. At the first stage of coupling after multitudinous rural surplus labor forces emerge. The farmers begin to go to city seeking jobs. In this period, the amalgamation of land management has not occurred and the single farmer's land has not yet concentrated. The total land area of single farmer has not yet increased and the total amount of farmers has not yet decreased. At the second stage of coupling, driven by living standards and income, multitudinous rural surplus labor forces begin to live in the city permanently in fact, and the scale management of rural land begins to arise. Foreign funded enterprises begin to enter agriculture, and the industrialization management of agriculture is equipped with the most fundamental conditions due to the occurrence of scaling up of land. At the third stage of coupling, the transfer of rural surplus labor forces basically ends. The properly rights of agricultural land or the management forms also, in a large measure, concentrate. The obstacles to agricultural scaling-up management are solved fundamentally, and the income gap between urban areas and rural areas is narrowed. Urban-rural population migration is no longer the main form of China's population migration. This stage has not yet been realized in China and it is the future state of villages. Finally, through the two cases researched by the predecessors, we verify the research results of the preceding two stages, which provides reliable reference for transformation of China's agricultural land management, and policy formulation of transfer of surplus labor forces.