In　order　to　study　the　shear　performance　of　high-strength　reinforced　partially-prestressed　UHPC　thin-web　beams　without　web　reinforcement,　shear　tests　were　conducted　on　seven　test　beams　with　different　shear　span　ratios　and　prestress　degrees　to　verify　the　assumption　of　plane　section,　and　to　analyze　their　bearing　capacity,　ductility,　angle　and　width　of　diagonal　cracks　on　the　beam,　stress　increment　and　deflection　of　prestressed　tendons.　The　results　show　that　the　test　beams　do　not　fully　meet　the　plane　section　assumption.　The　ultimate　bearing　capacity　decreases　with　the　increase　of　the　shear　span　ratio　and　increases　with　the　increase　of　the　degree　of　prestress　while　the　variation　of　ductility　is　opposite.　The　critical　shear　angle　and　width　decrease　with　the　increase　of　shear　span　ratio　and　prestress　degree.　The　stress　increment　of　prestressed　tendons　under　the　same　load　decreases　with　the　decrease　of　shear　span　ratio　and　the　increase　of　prestress　degree.　The　bigger　the　prestress　degree　in　elastic　stage,　the　greater　the　value　of　the　inverse　arch　and　the　smaller　the　deflection.　The　larger　the　shear　span　ratio　in　the　elastic-plastic　stage,　the　greater　the　deformation　of　the　beam,　and　the　faster　the　stiffness　degradation.　Recommended　formulas　for　calculating　shear　capacity　of　partially　prestressed　UHPC　beams　with　high　strength　reinforcement　are　proposed.　©　2019,　Department　of　Journal　of　the　China　Railway　Society.　All　right　reserved.