Given　that　the　traditional　three-phase　LCL-type　grid-connected　inverter　controller　needs　an　accurate　mathematical　model　to　have　good　control　performance,　this　paper　introduces　the　Differential　Flatness-based　Control　(FBC)　strategy　into　the　power　outer-loop　controller　of　grid-connected　inverter,　which　does　not　need　accurate　mathematical　model　and　has　good　tracking　ability.　In　addition,　the　Linear　Active　Disturbance　Rejection　Controller　(LADRC)　is　introduced　on　the　basis　of　the　FBC　to　improve　the　influence　of　inverter　coupling　and　uncertain　disturbance　on　the　system,　and　the　anti-disturbance　capability　of　LADRC　is　also　analyzed.　The　simulation　results　under　different　working　conditions　based　on　MATLAB/Simulink　software　show　that　the　proposed　FBC+LADRC　control　strategy　not　only　has　good　voltage　tracking　ability,　but　also　has　good　current　output　ability　in　the　case　of　grid　voltage　amplitude　disturbance.　©　2022　IEEE.