Grain security concerns the national economy and people’s livelihood and ensuring grain security as a bottom-line task has become the consensus of the whole society. The Government advocates the development of new agricultural business entities such as family farms to ensure grain security, however growing cash crops instead of grain crops is still a prominent problem. It is of great significance to study the “non-grain production” behavior of family farms. Based on a survey data of Xuzhou and its surrounding areas in Jiangsu Province and applying the expanding the concentric circle model of distributed cognitive theory, this paper built a theoretical framework to analyze the factors influencing family farms’ grain growing willingness under the bottom-line of grain security and to explore the corrective measures to improve the willingness of family farms to grow grain. Results show that among the survey samples, only 5.55% of family farms explicitly expressed their willingness to grow grain, and about 12.35% were willing to gradually switch to grain crops. Among the four variables of the distributed cognitive concentric circle model: personal force, asset force, regional force, and cultural force, the resource constraints and the social environment represented by the regional force, as well as the evaluation and satisfaction of the local culture represented by the cultural force have significant positive impacts on family farms’ willingness to grow grains. While the individual characteristics and experience represented by the personal force, as well as the asset specificity level represented by the asset force, have significant negative impacts. Therefore, to improve the willingness of family farms to grow grain, it is necessary to give a full play to the administrative compulsion of the government in the regional force and the moral restraint in the cultural force.