The　conventional　unified　power　quality　controller　(UPQC)　control　strategy　based　on　power　angle　control　enables　series　converters　to　share　the　burden　of　shunt　converters,　but　when　the　power　supply　voltage　has　both　amplitude　and　phase　changes,　The　phase　of　the　load　will　have　a　sudden　change,　which　will　affect　the　phase-sensitive　load.　Therefore,　this　article　proposes　a　constant　power　angle　control　of　the　energy　storage　type　UPQC　control　strategy.　Based　on　the　realization　of　the　coordinated　distribution　of　the　power　of　series　and　shunt　converters,　the　phase　of　the　load　voltage　is　not　affected　by　the　phase　jump　of　the　power　supply　voltage　within　a　certain　range.　The　capacity　configuration　of　the　series　and　shunt　converters　can　realize　the　function　of　uninterruptible　power　supply.　The　simulation　results　show　that　the　proposed　strategy　can　achieve　the　above　functions.　©　2021　IEEE.