Sewage　sludge　supercritical　water　gasification　in　fluidized　bed　reactor　was　studied　in　this　work.　Effect　of　temperature　on　the　distribution　of　products　and　gas　compositions　were　researched.　In　order　to　improve　the　gasification　process　more　effectively,　the　effect　of　temperature　on　reaction　process　development　and　gas　products　generation　was　also　studied.　A　variety　of　analytical　methods　were　used　to　study　the　detailed　characteristics　of　products　generated　at　different　reaction　conditions.　The　variation　of　product　yield　distribution　and　products　properties　showed　that　organic　matter　in　sewage　sludge　was　completely　dissolved　and　hydrolyzed　at　480　°C.　Multiple　reactions　happened　in　these　dissolved　and　hydrolyzed　products　and　then　gas　products　were　formed　when　temperature　increased　from　480　to　540　°C　further.　At　the　same　time,　dehydrogenation　and　polymerization　also　took　place　in　the　solution　and　hydrolyzed　products,　and　it　could　be　explained　by　the　Diels-Alder　reaction　mechanism　well.　©　2021　Elsevier　Ltd