Negative　photoconductivity　(NPC)　exhibits　great　potential　in　the　field　of　photodetection　due　to　low　power　consumption　and　high　response.　Herein,　the　photodetectors　based　on　InSe　and　multilayer　graphene　(MLG)/InSe　van　der　Waals　heterostructure　are　fabricated.　The　InSe　photodetector　shows　positive　photoconductivity　(PPC)　behavior,　while　the　MLG/InSe　photodetector　exhibits　NPC　behavior.　The　ultra-high　responsivity　(1.88　x　10(5)　A/W)　is　achieved　for　the　NPC　MLG/InSe　photodetector,　which　is　five　orders　of　magnitude　higher　than　that　of　the　sole　InSe　photodetector　based　on　PPC　(6.97　A/W).　The　MLG/InSe　photodetector　also　shows　a　high　external　quantum　efficiency　(6.41　x　10(7)%)　and　a　fast　response　time　(22　ms).　The　proposed　high-performance　MLG/InSe　heterostructure　photodetector　based　on　NPC　for　low　-dimensional　materials　may　extend　applications　in　future　optoelectronic　devices.(c)　2022　Vietnam　National　University,　Hanoi.　Published　by　Elsevier　B.V.