Abstract: Agricultural production trusteeship, as a main service and management mode of socialized service, is an important path to achieve the organic connection between small farmers and modern agricultural development. It is also critical to ensure national grain security. From the reality background and policy requirement and from the perspective of generative logic, this paper analyzed the internal mechanism, discussed the main problems, and provided some promotion strategies of agricultural production trusteeship to ensure national grain security. Results show that the generative logic of agricultural production trusteeship is composed of logical basis, generative conditions, manifestation, main purpose, and important premises. It plays an important role in ensuring national grain security by stabilizing property rights, improving production efficiency, decreasing input investment, reducing costs and risks, and improving the level of mechanization and informatization. However, agricultural production trusteeship also faces some challenges, including imperfect service system, prominent contradiction between supply and demand, unclear service object positioning, insufficient enthusiasm of service organizations. Therefore, to promote the development of agricultural production trusteeship, this paper provides the following suggestions: establishing a new grain production trusteeship service system, improving the service capacity of grain production trusteeship service organizations, promoting the active participation of small farms, and perfecting the support mode of grain production trusteeship policy.