Introduction:　Truss　core　material,　which　is　a　new　type　of　ultra-light　material　with　comprehensive　properties,　is　used　in　the　aerospace　industry.　The　aim　of　this　paper　is　to　investigate　the　dynamic　behavior　of　three-dimensional　Kagome　sandwich　plates　with　truss　core　under　transverse　and　in-plane　excitation　in　the　case　of　1:1　internal　resonance.　Methods:　Firstly,　the　averaged　equation　is　obtained　by　means　of　the　method　of　multiple　scales.　Then,　the　nonlinear　system　is　analyzed　applying　the　theory　of　normal　form.　Eventually,　we　analyze　the　dynamic　behavior,　mainly　periodic　motions,　for　the　truss　core　sandwich　panels　by　using　numerical　simulation.　Results:　Numerical　results　are　presented　here　for　the　nonlinear　dynamic　behavior　of　the　model　of　truss　core　sandwich　plates,　which　provides　theoretical　guidance　to　vibration　control.　Conclusions:　Considerable　insight　has　been　gained　concerning　the　sign　of　parameter　of　the　model　controlled　by　material　property.