In　response　to　the　new　requirements　for　face　gear　transmissions　in　the　latest　heavy-load　helicopters,　this　paper　investigates　the　impact　of　pressure　angle　variations　on　the　geometric　contact　and　performance　of　asymmetric　face　gears.　Firstly,　using　meshing　theory,　the　tooth　surface　equations　for　asymmetric　rack　cutter,　shaper,　and　face　gear　are　derived,　and　the　parameterized　3D　models　are　created.　Secondly,　the　line　of　action　(LOA),　contact　ratio,　contact　point　curvature,　and　load　sharing　ratio　considering　multi-pair　contact　(MPC)　under　different　pressure　angles　are　analyzed.　Then,　a　wear　calculation　model　based　on　the　Archard　wear　equation　is　developed,　detailing　the　tooth　surface　wear　depth　calculation.　Finally,　a　case　study　calculates　the　contact　stress　and　wear　depth　under　different　pressure　angles　is　presented.　The　results　indicate　that　appropriately　increasing　the　pressure　angle　effectively　lower　the　contact　stress　and　wear　depth　on　tooth　surface,　although　further　increases　degrade　meshing　performance.　The　gear　pair　with　a　pressure　angle　of　30°　in　the　case　study　exhibits　optimal　performance.　This　study　provides　a　reference　for　optimizing　asymmetric　face　gear　meshing　performance　under　various　pressure　angles.　©　IMechE　2025.