Abstract: Though the major grain-producing areas policy was introduced to motivate farmers’ enthusiasm for grain production and ensure national food security, we should further emphasize the development of green and ecological agriculture to meet the consumers’ requirements for high-quality products under the new situation. Based on a research region carried out in the 13 major grain-producing areas established by the government, we performed double difference model and mediation effect model to evaluate the comprehensive incentive policy’s impacts on farmers’ enthusiasm for grain production and explored its inner mechanism. We found that the policy had stimulated farmers’ enthusiasm for grain production with a dynamic cumulative effect. The policy could enhance farmers’ willingness to grow cereal but had no significant influence on the cultivation of legumes and potatoes. Additionally, the increase of non-agricultural income and welfare income would reduce the impacts of the policy. In spite of the above results, the major grain-producing areas policy could not improve the agricultural ecological efficiency significantly, and hence impeded the intermediary transmission process of the policy. To cope with this dilemma, it was proposed to guarantee the long-term stability of the major grain-producing areas policy, to be aware of the income and occupation differentiation of famers, to provide precise subsidies to large grain-producing farmers and the professional farmers who cultivated with the new type. It was also proposed to adjust the subsidies differentiation between ordinary and green high-quality grain to encourage farmers to produce high-quality agricultural products, to highlight the goal of increasing farmers' income, and to consider the direct subsidies for grain-producing farmers as the focus of the policy.