Motion　capture　system　can　transform　motion　information　of　human　body　into　digital　data　for　analysis　and　processing　in　computer　or　cyberspace.　It　is　an　important　medium　to　connect　physical　space　and　cyberspace.　Aiming　at　the　problems　of　high　cost　and　high　power　consumption　of　existing　inertial　motion　capture　systems,　this　paper　proposes　a　wearable　wireless　motion　capture　system　based　on　nine-axis　inertial　sensor　and　Bluetooth　Low　Energy　technology.　The　system　can　capture　the　motion　trajectory　of　human　body　and　realize　real-time　human　motion　display　and　data　storage　in　computer.　An　explicit　complementary　filtering　algorithm　based　on　proportional　integral　model　is　used　in　the　process　of　character　motion　update.　Motion　capture　experiments　are　carried　out　on　a　human　body　and　results　show　that　the　system　has　sound　dynamic　performance　with　the　error　less　than　2　degrees　and　can　achieve　efficient　human　motion　capture.　The　sampling　frequency　of　the　system　reaches　125Hz　and　the　working　time　is　up　to　10　hours.　The　system　can　serve　as　the　basis　for　developing　affordable　human　motion　capture　solutions　that　require　long-term　testing　without　precise　kinematic　analysis.　©　2022　IEEE.