Noncarrier　injection　(NCI)　operation　mode　is　an　emerging　driving　mode　for　nanoscale　light-emitting　diodes　(LEDs)　for　application　in　nanopixel　light-emitting　displays.　However,　the　luminescence　intensity　of　the　NCI-LED　with　traditional　epitaxial　structure　is　relatively　low　because　of　the　absence　of　external　carrier　injection.　Therefore,　improving　the　luminescence　intensity　by　optimizing　the　epitaxial　structure　of　the　LED　is　an　important　technical　measure.　In　this　work,　the　tunneling　behavior　of　the　NCI-LED　under　reverse　bias,　which　plays　a　key　role　in　increasing　the　luminescence　intensity,　is　studied　through　modeling　and　simulation.　The　dynamic　variation　of　carrier　concentration　in　each　voltage　cycle　is　studied　to　explore　the　working　process　of　the　NCI-LED.　Results　show　that　the　luminescence　output　of　the　NCI-LED　is　highly　sensitive　to　doping　concentrations,　and　reducing　the　number　of　multiquantum　wells　can　increase　the　probability　of　interband　tunneling　so　as　to　improve　dramatically　the　carrier　number　contributing　to　luminescence.　This　simulation　work　can　deepen　the　understanding　of　the　NCI　mode　and　serve　as　an　important　guidance　for　the　rational　design　of　the　NCI-LEDs.