We　propose　an　efficient　scheme　for　deterministic　one-step　generation　of　three-particle　Greenberger-Horne-Zeilinger　(GHZ)　state　in　a　bimodal　cavity　based　on　quantum　Zeno　dynamics,　which　reduces　the　complexity　of　the　experiment　operations.　The　cavity　modes　are　not　excited　in　the　evolution　and　the　influence　of　atomic　spontaneous　emission　and　the　cavity　decay　is　also　discussed　by　numerical　calculation.　The　results　demonstrate　that　the　scheme　is　robust　against　the　cavity　decay.