Dioxin　(DXN)　produced　by　municipal　solid　waste　incineration　(MSWI)　processes　is　a　highly　toxic　pollutant　with　unclear　mechanism　up　to　date.　It　is　important　to　understand　the　boundary　conditions　of　the　formation,　combustion　and　regeneration　of　DXN　in　the　grate　furnace　for　reducing　pollution　emissions.　In　this　paper,　a　numerical　simulation　method　of　DXN　emission　concentration　in　grate　furnace　incineration　processes　for　municipal　solid　waste　was　presented.　First,　according　to　the　MSWI　processes　flow　of　a　typical　grate　furnace,　the　mechanism　of　DXN-related　reactions　such　as　solid-phase　combustion,　gas-phase　combustion,　high-temperature　heat　exchange　and　low-temperature　heat　exchange　in　the　incinerator　was　described.　Then,　according　to　the　above　divided　areas,　a　numerical　simulation　model　combined　with　the　relevant　parameters　of　actual　MSWI　process　was　constructed.　Finally,　a　univariate　analysis　was　performed　based　on　the　reactant　concentrations　characterized　by　the　flue　gas　split　fraction　and　the　reaction　temperatures　in　different　regions　to　obtain　the　boundary　conditions　for　the　DXN　concentration　at　G1.　The　effects　of　split　fraction　and　reaction　temperature　on　the　DXN　concentration　at　G1　were　analyzed　based　on　orthogonal　experiments,　and　the　optimal　parameter　combination　was　obtained.　The　validity　of　the　model　was　proved　by　numerical　simulation　analysis　and　verification　based　on　the　actual　data　of　a　MSWI　power　plant　in　Beijing.　It　will　provide　support　for　the　subsequent　optimal　control　of　DXN　emission　concentration　at　G1.　©　2023　Chemical　Industry　Press.　All　rights　reserved.