Scientific simulation and regulation of cultivated land use structure is an important means to realize the optimization of planting structure, and it is of great significance to alleviate the structural contradiction between food supply and demand. Taking the typical counties in the black soil area of Northeast China as an example, a system dynamics (SD) model of cultivated land use was built to predict the planting area, yield and income of the main food crops: rice, corn and soybean. Based on the multi-scenario simulation, including economy, technology and market, the regulation path of cultivated land use structure was proposed. The results showed that the SD model had a good simulation effect, and the average deviation was less than 10%. It was predicted that from 2019 to 2030, the acreage of rice and soybeans would gradually increase, and the acreage of corn would decrease slowly. The yield of rice and corn would both increase, and the yield of soybean would increase first and then decrease. There were obvious differences in the simulation results of the three crops under different scenarios. The improvement of GDP level, the increase of agricultural technology input and the regulation of agricultural product prices would be beneficial to the increase of rice planting area, yield and income. Raising farmers’ income levels, strengthening agricultural technical support and regulating agricultural prices would significantly promote the increase of soybean planting area, yield and income in the future. However, the regulation of farmers’ income, agricultural technology and agricultural product prices had little effect on improving the cultivated land use structure of corn. The optimization of cultivated land use structure can be achieved by establishing a subsidy policy for planting structure adjustment, promoting the transformation and upgrading of agricultural mechanization, and improving the agricultural product market system. The research systematically explained the relationship between the factors of cultivated land use and the internal logic of structural changes, and clarified the regulation path of the cultivated land use structure of main food crops under different scenarios, providing a basis for the formulation of regional optimization policies for the future grain production structure, and for realizing the dynamic balance of food supply and demand. It was of great significance to promote the efficient and sustainable use of cultivated land resources.