When　hydraulic-legged　robots　move　under　high　loads　on　irregular　ground,　they　are　vulnerable　to　ground　impacts.　Vibration　affects　the　motion　performance　of　the　robot　and　damages　its　mechanical　structure.　This　study　aims　to　improve　the　properties　of　vibration　absorption　and　impact　resistance　of　hydraulic-legged　robots.　Because　the　traditional　MR　damper　(MRD)　has　small　output　in　finite　volume,　a　novel　MRD　with　a　multistage　flow　channel　(MFC-MRD)　can　output　a　large　damping　force　designed.　First,　an　MRD　prototype　was　designed　for　a　mechanical　leg’s　driving　joint.　Subsequently,　the　system　is　analyzed　theoretically,　and　a　semi-active　control　strategy　is　designed　and　simulated.　Finally,　the　vibration　and　impact　resistance　of　the　prototype　were　tested.　The　experimental　results　show　that　in　the　signal　tracking　experiment,　the　maximum　overshoot　under　semi-active　control　was　reduced　by　53.0%,　and　the　settling　time　was　reduced　by　76.9%　compared　with　the　passive　control.　The　impact　test　reduced　the　maximum　displacement　fluctuation　by　41.09%,　and　the　buffer　time　is　only　0.24 s.　©　The　Author(s)　2024.