An emerging and pressing issue in China’s economic reform is the intensified conflict between arable land protection and the encroachment of urban development into fertile farmlands that threaten food security and urban sustainability. New policies were issued to encourage rural land circulation as an attempt to ensure urban development and a sustainable food system, but farmers’ willingness to adopt the policies is largely unknown. A total of 4500 farmers within 9 cities’ boundaries in the Pearl River Delta were surveyed, and the theory of planned behavior and statistical tools were used to determine key factors affecting farmers’ attitudes towards the new sustainability policy. The results indicate that farmers’ cognition of the policies positively influenced farmers’ willingness to participate in land circulation. Attitude toward the Behavior (AB), Subjective Norm (SN), and Perceived Behavioral Control (PBC) were the dominant factors affecting the policies’ implementation. PBC had the most significant influence on sustainable policy participation, followed by SN and AB. AB alone could not determine the actual participation behavior because of external factors such as family, community, and other policy-related considerations. In conclusion, the successful implementation of the rural land-use policy will be primarily determined by the farmers’ cognition and behavior.