To　reduce　carbon　emissions　and　increase　the　efficiency　of　internal　combustion　engines　(ICEs),　it　is　necessary　to　use　renewable　alternative　fuels　and　to　use　Miller　cycle　technology.　Ammonia　is　an　energy　storage　medium　as　well　as　a　hydrogen　storage　medium.　In　this　experiment,　a　Miller　cycle　ICE　using　ammonia-hydrogen　fuel　was　investigated　at　1500　rpm　and　60%　throttle　opening.　The　excess　air　factor　of　1　and　the　ammonia　volume　share　of　70%　were　maintained　during　the　experiment.　The　objective　of　the　experiment　was　to　vary　the　intake　valve　timing　and　investigate　its　effect　on　engine　performance.　The　results　show　that　when　the　intake　valve　timing　is　advanced　and　the　valve　overlap　angle　is　kept　larger,　the　combustion　stability　deteriorates,　the　flame　development　period　(CA0-10)　is　prolonged,　the　cycle　variation　increases,　COVpmax　will　exceed　25%,　and　the　brake　thermal　efficiency　(BTE)　quickly　dropped　from　32.8%　to　30%.　When　the　intake　valve　timing　is　retarded　by　25　degrees　CA,　IMEP　and　BMEP　can　be　increased　by　8%　and　16%　compared　with　the　minimum　values.　Generally　speaking,　the　Miller　cycle　hydrogen-enriched　ammonia　engine　is　not　suitable　for　the　early　opening　strategy　of　the　intake　valve.