To　reduce　the　impact　force　when　the　foot　end　of　the　legged　robot　is　in　contact　with　the　ground　and　improve　its　flexibility,　a　new　type　of　series-parallelhybrid　leg　structure　is　proposed.　This　structure　is　driven　by　the　motor　and　is　designed　on　different　axes　of　the　hip　joint　to　reduce　processing.　It　is　difficult　to　increase　the　space　utilization　rate　simultaneously,　and　the　spring　device　is　used　to　achieve　good　passive　compliance.　The　co-simulation　of　Adams　and　MATLAB　is　used　to　verify　the　active　and　passive　compliance　effects.　The　experimental　results　show　that　the　single-leg　structure　proposed　in　this　paper　has　good　passive　compliance　characteristics,　and　the　admittance　control　can　be　used　to　realize　its　active　compliance　control.　©　2021　IEEE