A　method　of　machining　the　internal　double-arc　spiral　bevel　gear　with　a　finger　milling　cutter　was　presented.　The　mathematical　model　of　the　internal　spiral　bevel　gear　tooth　profile　was　established　considering　the　principle　of　machining　a　spiral　bevel　gear　by　the　generating　method,　and　a　three-dimensional　(3D)　tooth　profile　graph　was　developed.　Subsequently,　by　applying　the　gear　meshing　theory,　the　3D　model　of　the　tooth　alignment　curve　for　the　finger　milling　cutter　was　established.　Based　on　the　tooth　surface　equation　of　crown　gear,　the　cutter　intercept　equation　was　derived.　The　cutter　was　divided　into　four　finger　milling　cutters　considering　the　design　difficulty　of　the　cutter,　which　is　used　to　manufacture　different　arc　segments　of　the　double-arc　tooth　profile,　respectively.　The　special　machining　tool　model　of　the　internal　spiral　bevel　gear　was　further　developed　by　using　SolidCam,　and　the　simulation　experiment　was　carried　out.　The　simulated　gear　model　was　compared　with　the　theoretical　gear　model　and　the　error　of　the　simulation　experiment　was　estimated.　Actual　machining　on　the　machine　tool　and　the　internal　spiral　bevel　gear　were　inspected.　The　maximum　error　is　0.035　mm,　and　the　minimum　error　is　0.005　mm.　The　machining　accuracy　meets　the　requirements.　The　feasibility　of　machining　the　internal　double-arc　spiral　bevel　gear　with　a　finger　milling　cutter　was　verified.