A　communication-less　secondary　frequency　control　method　based　on　mode-switching　is　proposed　in　this　paper　to　compensate　for　the　frequency　deviations　in　the　islanded　microgrids　consisting　of　several　distributed　generators　connected　in　parallel,　where　the　droop　control　strategy　is　applied.　To　realize　this,　the　secondary　controller　changes　its　control　strategy　during　the　secondary　control　processes.　In　detail,　after　the　secondary　control　is　triggered　by　obvious　frequency　deviations,　the　secondary　controller　switches　to　the　first　mode　to　make　the　output　power　of　each　distributed　generator　be　the　same　through　a　proportional　regulator.　Then,　the　secondary　controller　switches　to　the　other　two　modes　in　turn　to　eliminate　the　frequency　deviations.　The　proposed　method　can　achieve　the　frequency　recovery　and　power　sharing　goals　of　secondary　control　at　the　same　time　with　communication-less　manner.　Meanwhile,　the　triggering　delay　phenomenon　is　verified　having　no　influence　on　the　proposed　method　compared　to　conventional　secondary　frequency　control　based　on　proportional-integral　regulator.　Both　software　simulation　and　hardware　experiments　are　used　to　verify　the　proposed　method.　©　2022　IEEE.