Supernumerary　robotic　limbs　(SRLs)　have　been　applied　in　fields　of　wearable　assistance　equipment　and　rehabilitation　therapy　with　good　performance　and　foreground.　In　view　of　the　shortcomings　in　the　current　SRLs　design　in　terms　of　versatility,　dexterity　and　interactive　performance,　this　paper　introduces　a　dexterous　hand　mechanism　for　robotic　function　conversion　and　develops　a　human-robot　interactive　control　system.　In　addition,　to　meet　the　diverse　rehabilitation　needs　of　patients,　a　virtual　task　environment　based　on　the　Unity　platform　is　built,　by　developing　an　interactive　VR　game　with　active　and　passive　rehabilitation　training　modes　and　completing　the　game　architecture　design　of　a　customizable　hand　grasping　virtual　reality　scene　combined　with　the　kinematic　configuration　analysis　of　dexterous　hands.　In　order　to　realize　its　intelligent　interactive　control,　a　double-layer　feedback　control　loop　based　on　force　and　speed　has　been　developed　to　realize　the　fine　motion　control　of　the　dexterous　hand,　and　the　output　torque　adjustment　of　the　dexterous　hand　is　realized　by　designing　the　deviation　threshold.　The　results　show　that　the　dexterous　hand　has　good　interactive　performance　in　hand　rehabilitation　and　human　muscle　strength　enhancement,　and　the　control　algorithm　has　good　accuracy　and　robustness.　©　The　Author(s),　under　exclusive　license　to　Springer　Nature　Singapore　Pte　Ltd.　2025.