The improvement of the legal system is a manifestation of the current “having grain in the land” and the “14th Five-Year Plan” strategy， but there is still a mix of “permanent basic farmland” and “basic farmland” in its institutional regulations. In this paper the “permanent basic farmland” is expounded around literary interpretation， theoretical interpretation， and sociological interpretation， and it is found that it is not very different from “basic farmland” and the former is more in line with existing practice. The research believes that the inconsistency of the upper and lower levels of legal provisions， the different conceptual terms used in the old and new policy documents， and the lack of a good permanent basic farmland legal system are all due to the ambiguity of the concept of “permanent basic farmland” and and the mixed use of “permanent basic farmland” and “basic farmland” in normative documents. Based on this， under the regulation and unification of the use of “permanent basic farmland” in policy documents such as laws and regulations， the existing legal system can be improved from the macro and micro levels. The macro-structure of system construction is embodied in three aspects： one is to update and improve the benign interaction between laws and regulations， the other is to strengthen the systemic connection of other laws， and the third is to timely respond to policy norms； the microscopic vision of system construction is expressed in the object clear scope delineation and integration of cultivated land compensation， strict application of the occupancy and compensation system， strengthened monitoring， supervision and governance under clear rights and obligations， and organic coupling of food security uses and ecological development.