In　order　to　make　full　use　of　renewable　energy　and　improve　the　utilization　of　wind　power,　a　new　joint　optimization　scheme　of　the　wind-hydrogen　system　coupled　with　transmission　project　is　proposed　in　this　paper,　in　which　wind　power　is　reasonably　allocated　for　grid　integration　and　for　hydrogen　production.　Aiming　at　maximize　the　annul　wind-hydrogen　system　benefit,　the　optimal　sizes　of　wind　power　transmission　project　and　hydrogen　system　are　obtained　under　different　hydrogen　production　modes,　hydrogen　trading　modes　and　hydrogen　demand　levels.　In　addition,　the　penalty　cost　of　wind　curtailment　and　hydrogen　supply　shortage　and　the　system　environmental　benefits　are　taken　into　account.　Results　show:　during　the　long-term　of　insufficient　of　wind　power,　it　is　better　to　produce　hydrogen　using　wind　power　and　grid-assisted　power　to　avoid　hydrogen　supply　shortage;　considering　the　future　increase　of　hydrogen　demand,　the　optimal　supply　number　of　hydrogen　refueling　stations　in　the　wind-hydrogen　system　is　two.　Also,　the　low　utilization　of　fuel　cells　means　that　the　benefit　from　regeneration　cannot　offset　the　high　cost,　which　leads　to　the　abnegation　of　fuel　cells　in　the　wind-hydrogen　system.　(C)　2020　Hydrogen　Energy　Publications　LLC.　Published　by　Elsevier　Ltd.　All　rights　reserved.