Biological　studies　have　shown　that　place　cells　have　a　single　firing　fields,　which　is　the　main　basis　for　rats　to　know　the　current　spatial　location.　The　grid　fields　is　hexagonal　in　the　form　of　the　whole　space　area.　Grid　cells　are　the　main　source　of　information　input　for　place　cells,　so　it　is　necessary　to　build　a　mapping　model　from　grid　cells　to　place　cells.　In　order　to　solve　this　problem,　an　iteration　model　from　grid　cells　to　place　cells　is　proposed.　The　model　iterates　the　activation　rate　matrix　of　grid　fields　with　different　grid　parameters　in　a　given　region,　and　realizes　the　mapping　of　grid　cells　to　place　cells.　On　this　basis,　a　single　place　fields　detection　algorithm　is　added　to　improve　the　accuracy　and　efficiency　of　the　model.　The　experimental　results　show　that　the　model　can　not　only　map　multiple　grid　fields　to　a　single　place　fields,　but　also　accurately　locate　the　rat＇s　position　in　a　given　region.