The basic feature of intertwining natural reproduction and economic reproduction in agricultural economic management determines its high risk. This paper calculates the marginal value of each variable input factor in the agricultural economic management mode through the total income function and analyzes the optimal combination between each variable input factor and agricultural output by combining with the theory of diminishing marginal returns so as to maximize the economic returns in the agricultural economic management mode and achieve the optimization of risk management and control in the agricultural economic management mode. The results of the example show that if the incremental index in the agricultural economic management model of Gansu Province is greater than the level of the previous year, the growth of expenses in the agricultural economy is considered effective. It is also found that the risk of natural disasters is the highest in the agricultural economic management model in Gansu Province, especially the average risk value of wind and hailstorms reaches 1.143, which is much higher than the risk of grain production (0.031), which has the lowest risk level. This paper provides an effective reference for optimizing the effective control of risk in the agricultural economic management model and lays the foundation for improving the economic efficiency of the agricultural economic management model.