The　brake　disc　of　a　high-speed　train　can　produce　huge　heat　in　the　process　of　steep　brake　or　parking　brake.　Thus　the　heat　transfer　characteristics　of　the　high-speed　train　brake　discs　are　the　basic　information　needed　to　design　them.　The　main　works　of　the　present　paper　are　to　establish　a　flow　model　that　is　similar　to　the　actual　brake　disc　working　conditions,　and　to　obtain　the　local　and　average　convective　heat　transfer　characteristics　of　the　outside　surface　of　vehicle　break　disc　experimentally.　The　naphthalene　sublimation　technique　of　heat/mass　transfer　analogy　method　is　used.　The　significant　result　is　that　the　diameter　ratio　of　the　brake　disc　to　the　wheel　determines　the　convective　heat　transfer　characteristics　on　the　vehicle＇s　brake　disc　outside　surface.　Due　to　the　influence　of　the　ground,　the　average　Nusselt　number　on　the　surface　of　a　break　disc　is　larger　than　that　of　a　rotating　disc　in　crossflow　at　the　same　Reynolds　number.　The　local　Nusselt　number　on　the　surface　of　a　break　disc　decreases　along　the　radius　direction.　The　correlations　of　the　local　and　average　Nusselt　numbers,　Reynolds　number,　and　the　diameter　ratio　of　brake　disc　to　wheel　are　established.　The　average　Nusselt　number　is　larger　than　that　on　the　surface　of　a　rolling　wheel　at　the　same　Reynolds　number.　(C)　2017　Elsevier　Masson　SAS.　All　rights　reserved.