Realizing　superior　mechanical　performance　and　outstanding　multifunction　features,　yet　with　lightweight　configuration,　simultaneously,　has　been　always　a　fundamental　challenge.　Here　we　design　and　experimentally　achieve　an　ultralight　framework　of　lattice-truss-core　sandwich　panels,　namely　meta-lattice　structure,　for　highly-efficient,　broadband　low-frequency　vibration　attenuation.　A　composite　meta-lattice　sandwich　panel　is　proposed　and　integrally　fabricated　with　glass　fiber　reinforced　Nylon　by　the　3D　printing　technique　of　selective　laser　sintering.　Requiring　neither　heavy　local-resonators　nor　soft　damping　support,　the　designed　meta-lattice　structure　can　generate　a　wide　low-frequency　bandgap,　where　the　bandwidth　has　a　remarkable　double-time　increment,　meanwhile　the　yield　strength　has　a　significant　improvement.　An　analytical　model　based　on　Rayleigh-energy　and　Euler-Bernoulli　beam　theory　is　presented　to　tailor　the　bandgap　characteristics.　Without　losing　lightweight　superiority,　our　meta-lattice　prototype　exhibits　absolute　advantages　in　broadband,　low-frequency　vibration　attenuation　and　high　loading-bearing　capacity,　which　offers　a　thriving　avenue　to　the　outstanding　integration　of　structural　strength　and　diverse-function　performance.　©　2022　Elsevier　Ltd