Industrial　structure　upgrading　(ISU)　is　a　crucial　step　towards　achieving　low-carbon　development　for　China.　This　paper　aims　to　assess　the　influence　of　ISU　on　agricultural　carbon　emissions　(ACE),　and　unveil　its　underlying　mechanism.　By　employing　the　Spatial　Durbin　Model　(SDM),　the　findings　demonstrate　that　ISU　has　a　significant　inhibitory　effect　on　ACE,　while　displaying　a　promoting　effect　on　ACE　of　neighbouring　regions.　Additionally,　transportation　infrastructure　and　population　density　have　an　intermediary　effect　in　the　relationship.　When　using　ISU　and　level　of　economic　development　as　a　threshold　variable,　ISU　exhibits　a　positive　impact　before　the　threshold,　and　a　negative　impact　after　the　threshold.　Furthermore,　this　study　reveals　regional　heterogeneity,　that　is,　ISU　has　varying　impacts　on　ACE　in　eastern,　central　and　western　China.