This　article　took　the　municipal　solid　waste　incineration　process　(MSWI)　based　on　the　grate　furnace　with　a　rated　capacity　of　800t/d　as　the　research　object.　The　numerical　simulation　method　of　coupling　solid-phase　combustion　on　the　grate　and　gas-phase　combustion　in　the　furnace　was　used.　This　article　was　carried　out　under　the　specific　process　parameters　of　a　factory,　such　as　MSW　calorific　value　of　8350kJ/kg,　total　air　volume　of　75000m3/h,　primary　air　temperature　of　500K,　and　secondary　air　temperature　of　300K.　The　grate　speed　of　8m/h　and　the　primary　and　secondary　air　distribution　ratios　of　0.91:0.09　were　used　as　the　benchmark　conditions.　The　effects　of　factors　such　as　grate　speed,　primary　and　secondary　air　ratio　on　the　temperature,　O2　mass　fraction　and　CO2　mass　fraction　in　the　incinerator　were　studied.　The　results　show　that:　1)　When　the　grate　speed　is　gradually　increased　from　6　m/h　to　12　m/h,　the　devolatilization　rate　and　char　burning　rate　gradually　decrease,　and　the　oxygen　consumption　decreases.　As　a　result,　the　peak　temperature　of　flue　gas　after　solid-phase　combustion　of　the　grate　gradually　decreases,　the　average　value　of　O2　and　CO2　mass　fraction　gradually　increases　and　decreases　respectively.　Finally,　the　flue　gas　temperature,　O2　mass　fraction　and　CO2　mass　fraction　at　the　outlet　of　the　third　flue　of　the　incinerator　fluctuate　with　relative　errors　of　1.2%∼2.5%,　1.0%∼3.9%　and　7.8%∼9.8%.　2)　When　the　primary　air　ratio　was　gradually　increased　from　0.84　to　0.96,　the　increase　in　flow　resulted　in　an　increase　in　the　amount　of　O2.　The　low　temperature　air　flow　brings　cooling　effect　to　the　combustion　reaction　area.　As　a　result,　the　peak　temperature　of　flue　gas　after　solid-phase　combustion　of　the　grate　gradually　decreases,　the　average　value　of　O2　and　CO2　mass　fraction　gradually　increases　and　decreases　respectively.　Under　the　influence　of　the　change　of　flue　gas　properties　and　the　gradual　decrease　of　the　secondary　air　volume,　the　flue　gas　temperature,　O2　mass　fraction　and　CO2　mass　fraction　at　the　outlet　of　the　third　flue　of　the　incinerator　fluctuate　with　relative　errors　of　0.1%∼2.6%、0%∼58.3%　and　9.8%∼88%.　©2022　Chin.Soc.for　Elec.Eng.