Hydrogen-fueled　Wankel　rotary　engine　is　considered　the　potential　carbon-free　power　device.　Due　to　the　special　structure　and　operating　mode,　the　heat　release　process　of　the　Wankel　rotary　engine　is　significantly　different　from　the　piston　engine.　To　understand　the　heat　release　process　and　further　optimize　its　combustion,　the　present　work　conducts　a　series　of　experiments,　such　as　engine　speed,　excess　air　ratio　and　qualitative　control　experiments,　to　analyze　the　key　combustion　parameters　under　different　conditions.　The　main　results　are　as　follows:　Both　engine　speed　and　excess　air　ratio　play　important　roles　in　flame　development　and　propagation.　In　particular,　the　excess　air　ratio　only　affects　the　early　stage　of　flame　propagation　due　to　its　impact　on　the　later　stage　is　covered　by　in-cylinder　turbulence.　CA0-10　is　prolonged　from　15.9　to　11.2°CA　while　CA50-90　does　not　show　regular　changes　when　the　excess　air　ratio　is　reduced　from　2.0　to　1.2.　For　qualitative　control　mode,　variation　of　combustion　parameters　will　become　the　obstacle　to　expanding　lean　flammable　limits.　In　particular,　the　distribution　of　CA10　and　CA50　or　CA90　and　CA50　can　be　fitted　by　linear　regression,　and　the　gradient　and　intercept　of　the　fitted　line　can　be　used　to　represent　engine　speed　and　excess　air　ratio.　1000　r/min　corresponds　to　1.07　gradient　and　2500　r/min　is　1.27.　NO　emission　is　closely　related　to　time-based　CA0-10　and　CA10-90　that　can　be　applied　as　the　independent　variable　of　the　Support　Vector　Machine　with　radial　basis　function　kernel　function　to　predict　NO　emission,　and　the　maximum　coefficient　of　determination　is　0.92.　©　2024　Hydrogen　Energy　Publications　LLC