This　paper　proposes　the　circuit　configuration,　circuit　topological　family　and　master-slave　power　management　SPWM　control　strategy　with　smooth　and　seamless　handover　in　different　power　supply　modes　of　quasi　single　stage　isolated　Buck-Boost　mode　multi-input　inverter.　The　circuit　configuration,　topologies,　power　management　strategy,　characteristic　of　steady　principle,　duty　ratio　relationship　of　the　multi-input　sources　and　design　criteria　for　key　circuit　parameters　are　fully　investigated.　The　circuit　configuration　is　composed　of　a　bidirectional　isolated　Buck-Boost　converter　with　multi-input　selected　switches　in　series　and　an　unfold　bridge,　including　four　topologies　such　as　one-transistor　mode.　The　master-slave　power　management　strategy　is　composed　of　n-1　input　voltage　loops,　n　power　distribution　circuits　and　instantaneous　output　voltage　loop　with　independent　power　control,　which　can　realize　smooth　and　seamless　handover　in　different　power　supply　modes.　The　designed　and　developed　500V•A　DC　80~110V/AC　220V　50Hz　prototype　of　multi-input　inverter　has　excellent　performances　such　as　high　conversion　efficiency,　high　quality　of　output　waveforms,　strong　load　adaptability,　smooth　and　seamless　handover　in　different　power　supply　modes.　©　2018,　Electrical　Technology　Press　Co.　Ltd.　All　right　reserved.