The　diglycidyl　ether　(HDDGE)　and　dicyclohexylmethane　diisocyanate　(HMDI)　are　widely　adopted　as　active　rejuvenators　in　the　field　of　regenerated　SBS　modified　bitumen　(RSMB),　which　can　react　with　the　oxygen-containing　functional　group　on　the　aged　SBS,　thereby　rebuilding　the　crosslinking　net　of　the　SBS.　Numerous　measurements　indicate　that　HDDGE　negatively　affects　the　high-temperature　performance　of　RSMB,　while　HMDI　impairs　its　low-temperature　performance.　This　unexplained　phenomenon　continues　to　impede　the　effective　regeneration　of　bitumen.　To　reveal　the　underlying　mechanism　of　this　phenomenon,　this　study　investigates　the　SBS-bitumen　interface　inside　the　RSMB　thought　the　molecular　dynamics　simulation,　and　conducts　the　experiments　in　the　lab　to　prove　the　inference.　Results　indicated　that　the　type　and　dosage　of　rejuvenators　will　affect　the　H-bonds　inside　regenerated　SBS,　which　will　change　the　configuration　of　SBS　molecules.　Subsequently,　the　regenerated　SBS　molecules　will　redetermine　the　fractions　located　at　the　SBS-bitumen　interface　thought　the　space　steric　hindrance　effect　and　interaction　between　SBS　and　bitumen,　which　will　alter　the　colloid　structure　of　RSMB.　This　will　significantly　change　the　free　volume　of　the　RSMB,　and　will　finally　affect　the　macro-properties　of　RSMB.　©　2025　Elsevier　B.V.