The　paper　proposes　a　smooth　transition　control　strategy　for　microgrids　with　high　power　quality　and　no　need　for　remote　communication　lines.　The　microgrid　is　mainly　composed　of　multiple　parallel　distributed　power　generation　units　and　a　pre-synchronization　unit.　A　unified　grid-connected　current　control　structure　is　proposed　for　the　interface　inverter　in　the　distributed　power　generation　unit,　which　has　the　following　advantages:　Without　island　detection,　the　inverter　can　automatically　switch　between　the　current　control　state　of　the　grid-connected　mode　and　the　voltage　control　state　of　the　stand-alone　mode　to　ensure　the　load　power　supply　quality;　The　proposed　unified　grid-connected　current　control　structure　can　effectively　suppress　the　harmonics　in　grid-connected　current　and　capacitor　voltage;　When　the　grid　frequency　fluctuates,　the　inverter　can　still　output　the　corresponding　active　and　reactive　power　according　to　the　command　value,　and　can　synchronize　with　the　grid　without　a　phase-locked-loop　or　a　frequency-locked-loop　in　the　grid-connected　operation　state.　In　addition,　the　proposed　pre-synchronization　unit　can　realize　the　pre-synchronization　control　of　the　microgrid　voltage　and　the　grid　voltage　without　relying　on　the　remote　communication　lines.　It　also　reduces　the　inrush　current　when　the　stand-alone　operation　state　changes　to　the　grid-connected　operation　state.　Finally,　the　control　parameters　are　optimized,　and　the　effectiveness　and　feasibility　of　the　proposed　control　strategy　are　verified　through　experiments.　©　2022,　Electrical　Technology　Press　Co.　Ltd.　All　right　reserved.