To　study　the　interface　friction　and　vibration　behaviours　of　brake　systems　with　wheel　flat,　a　rigid-flexible　vehicle　dynamics　model　and　a　finite　element　model　of　brake　system　are　developed.　These　two　models　are　validated　using　experimental　test　data.　Additionally,　an　analysis　formula　of　brake　system　excited　by　wheel　flat　is　proposed　to　reveal　the　tribological　behaviours.　The　results　indicate　that　the　wheel　flat　directly　induces　the　elastic　vibration　of　brake　disc　and　further　affects　the　disc　contact,　resulting　in　a　significant　increase　in　the　contact　force,　contact　stress,　friction　force　and　vibration　acceleration　between　the　brake　interfaces.　Furthermore,　the　proposed　model　can　be　used　to　investigate　the　related　tribological　behaviour　of　brake　systems　under　other　complex　wheel-rail　excitations.