The　oval　rotary　engine　(ORE)　has　smooth　rotation,　high　power　density,　and　a　more　flexible　combustion　chamber　shape　than　the　Wankel　rotary　engine,　with　a　great　future　in　carbon-free　power.　This　ORE　numerical　model　works　with　the　hydrogen　direct-injection　and　spark　ignition　to　study　the　impact　of　different　spark　plug　positions,　ignition　timings,　and　excess　air　ratio　(2)　on　the　engine　performance.　The　results　indicate　that　high　turbulence　occurring　near　the　top　dead　center　(TDC)　in　the　combustion　chamber　edge　accelerates　flame　propagation　on　trailing　spark　position　in　combustion　chamber.　The　case　with　the　spark　position　on　the　trailing　side　of　the　combustion　chamber　has　the　shortest　ignition　delay　period　of　3.9　degrees　crank　angle　(CA)　and　main　combustion　period　of　11.7　degrees　CA.　In-cylinder　vortices　become　smaller　and　hydrogen-air　mixing　becomes　poorer　with　delaying　ignition.　Mixture　stratification　in　rich　mixture　results　in　NOx　emission　of　the　case　with　2　of　1.4　27　%　lower　than　2　of　1.6.　Overall,　the　optimal　working　condition　is　2　of　1.8　with　ignition　at　6　degrees　CA　before　TDC,　which　is　21　%　higher　on　IMEP,　just　0.9　%　lower　on　ITE　of　36.4　%,　but　19.4　%　higher　on　NOx　emission　than　the　case　with　ultra-lean　mixture.