China　faces　challenges　of　food　security　and　sustainable　agricultural　production.　However,　current　studies　rarely　address　the　spatial　distribution　patterns　of　water　consumption　and　carbon　emissions.　We　studied　the　irrigation　water　use　efficiency　and　carbon　emission　differences　of　crops　in　arid　areas　and　their　spatial　distribution　using　wheat　and　maize,　two　major　food　crops　in　the　middle　reaches　of　the　Heihe　River,　as　examples.　Furthermore,　we　have　optimized　low-carbon　cropping　of　crops　under　the　multiple　objectives　of　water　conservation　and　economic　development.　The　results　show　that:　(1)　The　carbon　emissions　per　unit　of　water　consumption　for　maize　are　0.03　x　10(-6)　t　mm(-1)　and　0.49　x　10(-6)　t　mm(-1)　for　wheat.　Irrigation　water　consumption　per　unit　yield　is　515.6　mm　t(-1)　for　maize　and　426.7　mm　t(-1)　for　wheat.　(2)　The　spatial　distribution　patterns　of　irrigation　water　consumption　were　opposites　for　maize　and　wheat.　The　former　has　lower　irrigation　water　consumption　in　the　planting　area　upstream　of　the　Heihe　River　and　higher　in　the　lower　reaches.　In　contrast,　the　pattern　of　wheat　irrigation　is　the　opposite.　(3)　After　optimizing　the　cropping　mix　for　both　crops,　the　area　planted　with　wheat　should　be　reduced　to　59%　of　the　current　size,　while　maize　should　be　expanded　to　104%.　The　results　of　the　research　hold　immense　importance　in　guiding　the　future　grain　crop　planting　patterns　for　water-saving　agriculture　and　low-carbon　agriculture　development　in　arid　zones　worldwide,　aligning　with　the　United　Nations＇　Sustainable　Development　Goals.