The　interleaved　parallel　technique　and　magnetic　integration　technique　can　effectively　improve　power　density　of　high-current　LLC　resonant　converter.　However,　its　common-mode　(CM)　noise　mechanism　and　suppression　are　complicated　due　to　the　integration　of　multiple　transformers　(IMTs)　sharing　one　common　core　in　the　interleaved　multiplexing.　The　CM　noise　mechanism　of　the　IMTs　is　analyzed,　and　the　structural　capacitance　model　and　common-mode　noise　model　of　the　IMTs　are　established.　The　model　reveals　that　there　exists　electric　field　coupling　between　the　any　two　windings　through　the　common　core　of　the　IMTs.　Then　the　CM　noise　propagation　mechanism　of　interleaved　LLC　resonant　converter　with　IMTs　is　investigated,　and　the　simplified　CM　noise　model　of　the　IMTs　is　further　developed.　Based　on　the　simplified　model,　the　two　suppression　methods　of　the　optimal　balance　capacitance,　and　the　grounding　both　of　shielding　layer　and　transformer　magnetic　core　are　proposed.　The　experiments　in　a　3　kW　high　power　density　server　power　supply　shows　that　the　proposed　suppression　methods　mitigate　CM　noise　more　effectively,　and　can　reduce　the　CM　inductor　volume　greatly,　while　loss　improvement　can　be　negligible.　The　experiments　validates　the　IMTs　noise　mechanism,　CM　noise　model,　the　simplified　model,　and　the　proposed　suppression　methods.　The　research　will　be　beneficial　to　develop　high　power　density　and　high　current　AI　server　power　supply.　　©　IEEE.　1982-2012　IEEE.