The rent of farmland transfer represents the economic realization of farmland contracts and management rights of agricultural households. A three-stage dynamic game model with three players is constructed in this paper to study the mechanism causing an increase in farmland transfer rent. Based on the theory of producer equilibrium and production possibility boundaries, this paper studies the restraining effect of high rent on grain production and analyzes the factors that prevent the decline in grain production at present. Combined with the process of farmland transfer in a village, both the mechanism causing an increase in farmland transfer rent and the restraining effect of high rent on grain production are empirically analyzed. The conclusion is as follows: the basic direction of farmland transfer is from farmers with a low production capacity to farmers with a high production capacity, and the rent level is determined by the transferors with high production capacity; about half of the economies of scale profits and two-thirds of transferees’ subsidies are converted into farmland transfer rents. High farmland transfer rent reinforces “nongrain” and “nonagricultural” behaviors. Finally, it is suggested that farmers should be given vocational training in agricultural production, “farmland transfer tax” should be levied on excessive farmland transfer rent, and transferees should be subsidized for grain production.