According　to　irregular　changes　in　rail　profiles　in　a　fixed-nose　crossing,　a　parametric　design　method　was　proposed　based　on　the　B-spline　theory　by　considering　the　section　characteristics　of　rail　profiles　in　a　fixed-nose　crossing.　In　addition,　the　rail　profile　fitting　evaluation　indexes　and　the　influence　weights　of　key　control　parameters　on　the　rail　profile　fitting　were　proposed.　With　No.12　turnout　of　fixed-nose　crossing　of　60　kg/m　rail　as　an　example,　the　design　of　experiment　(DOE)　was　employed　to　analyze　the　influence　of　railhead　slope,　rail　side　slope,　and　proportion　coefficient　of　composite　circular　arc　on　the　changes　in　the　full　railhead　profile,　rail　top　profile,　and　rail　side　profile　of　the　nose　rail.　The　results　show　that　1)　for　nose　rail　with　a　section　of　20　mm,　the　influence　weights　of　railhead　slope,　rail　side　slope,　and　proportion　coefficient　of　composite　circular　arc　on　the　full　railhead　profile　change　are　21.08%,　56.89%,　and　22.02%,　respectively,　and　the　influence　weights　on　the　rail　top　profile　change　of　the　nose　rail　are　8.42%,　61.95%,　and　29.63%,　respectively.　For　nose　rail　with　a　section　of　50　mm,　the　influence　weights　of　the　key　control　parameters　on　the　full　railhead　profile　change　are　55.9%,　33.38%,　and　10.72%,　respectively.　For　nose　rails　with　a　section　of　20　mm　and　50　mm,　the　influence　weights　of　the　rail　side　slope　on　the　rail　side　profile　change　are　76.82%　and　66.04%,　respectively.　2)　When　the　nose　railhead　width　is　20　mm,　the　influence　of　the　rail　side　slope　on　the　nose　profiles　is　more　than　50%.　As　the　nose　railhead　width　increases,　the　influence　weight　of　railhead　slope　on　full　railhead　profile　gradually　increases　from　21.8%　to　55.9%,　while　that　of　rail　side　profile　and　proportion　coefficient　of　composite　circular　arc　is　reduced　by　41.3%　and　51.3%,　respectively.　©　2024　Science　Press.　All　rights　reserved.