Prefabricated　ultra-high　performance　concrete(UHPC)channel　segments　are　connected　by　dry　joints　and　prestressed　tension　to　form　a　channel　girder,　which　is　then　combined　with　a　cast-in-place　concrete　slab　to　form　a　composite　girder,　which　is　called　as　prestressed　UHPC　composite　segments　girder　with　monolithic　concrete　slab(PUCS-MCS　composite　girder).　It　is　a　new　type　of　bridge　structure　that　can　fully　utilize　the　performance　of　different　materials,　provide　good　overall　performance,　and　is　easy　to　be　constructed.　To　explore　its　shear　behavior,　experimental　study　was　conducted　on　the　shear　behavior　of　nine　specimens　with　the　parameters　of　dry　joint　number,　number　of　the　shear　keys　in　the　joint,　shear-to-span　ratio,　steel　fiber　volume　fraction　of　UHPC,　stirrup　ratio,　and　longitudinal　reinforcement　ratio.　The　effects　of　each　parameter　on　the　deflection,　failure　mode,　and　shear　capacity　of　the　specimens　were　analyzed.　Based　on　the　experimental　study　results,　a　formula　was　proposed　for　predicting　the　shear　capacity　of　PUCS-MCS　composite　girder.　The　results　show　that　the　PUCS-MCS　composite　girders　are　all　failed　in　shear　compression.　The　load-deflection　curves　of　all　specimens　are　similar　before　cracking,　and　the　stiffness　of　the　PUCS-MCS　composite　girders　weaken　more　significantly　than　that　of　monolithic　girder　without　joint　after　cracking.　The　shear　capacity　of　PUCS-MCS　composite　girders　increases　with　the　number　of　the　shear　keys　in　the　joint,　the　steel　fiber　volume　fraction　of　UHPC,　the　stirrup　ratio,　and　longitudinal　reinforcement　ratio,　and　decreases　with　the　dry　joint　number　and　shear-to-span　ratio.　Among　these　parameters,　the　most　significant　effects　are　induced　by　the　number　of　shear　keys　and　dry　joints,　and　the　least　are　the　steel　fiber　volume　fraction　and　the　stirrup　rate.　Therefore,　a　PUCS-MCS　composite　girder　can　be　made　without　stirrup,　and　the　UHPC　can　be　mixed　with　low　steel　fiber　volume　fraction.　©　2024,　Editorial　Department　of　Journal　of　Architecture　and　Civil　Engineering.　All　rights　reserved.