To find out the spatial pattern of comprehensive grain potential, we chose α, Ri, Yi from the research output of farmland grading and took them as the basic data; using the Aggregated Advantage Indices and hierarchical cluster analysis methods, finally regionalized all the 12 counties into 4 regions :ⅠHigh potential—regions easy to be mined in the short term, Ⅱ High potential—regions that can be mined in the long term, Ⅲ Low potential—regions easy to be mined in the short term, Ⅳ Low potential—regions difficult to be mined in the long term. From the study results, we also find out that the Scale Advantage Indices of farmland (SAI) has a strong positive effect on the Aggregated Advantage Indices of grain potential (AAI), so we conclude that it is necessary to maintain and increase a certain amount of farmland area to ensure the regional grain production capacity.