Composite　sandwich　structure　with　carbon　fiber　reinforced　polymer　(CFRP)　square　honeycomb　core　was　designed　and　fabricated　using　the　interlocking　method.　The　out-of-plane　compressive　performance　and　the　three-point　bending　performance　of　the　sandwich　structure　were　studied　experimentally.　The　failure　modes　of　the　sandwich　structure　under　out-of-plane　compressive　loading　were　obtained　and　the　failure　mechanism　and　energy　absorption　characteristics　were　analyzed.　The　influences　of　the　asymmetry　of　the　face　sheet　quality　and　the　direction　of　the　slots　on　the　failure　modes　and　bending　strength　of　the　sandwich　beam　under　three-point　bending　loading　were　explored,　respectively.　The　experimental　results　show　that　the　sandwich　structure　under　out-of-plane　compressive　loading　exhibits　the　progressive　failure　mode:　fiber　fracture　near　the　slots,　bucking　and　fracture　of　the　slotted　part　of　ribs,　and　the　fracture　and　crushing　of　the　unslotted　part　of　ribs.　The　compressive　stress-strain　curve　has　obvious　two-stage　plateau　stress,　which　means　the　excellent　energy　absorption　characteristics　of　the　sandwich　structure.　The　sandwich　structure　has　the　higher　load-carrying　capacity　and　initial　failure　loading　for　the　thicker　upper　face　sheet　and　the　upward　slots　of　the　long　ribs　of　the　core.　Copyright　©2022　Acta　Materiae　Compositae　Sinica.　All　rights　reserved.