For　resonant-type　meta-structures　with　finite　dimensions　and　consisting　of　multiple　units,　their　sound　absorption　performance　varies　with　the　placement　of　the　units.　In　order　to　reveal　the　physical　mechanism　of　this　phenomenon　and　obtain　the　structural　design　rules　to　achieve　optimal　sound　absorption　performance,　the　acoustic　critical　absorption　effect　is　proposed　in　this　paper.　Based　on　this,　a　50　mm　thick　meta-structure　is　proposed,　which　obtains　an　average　sound　absorption　performance　of　70　%　from　1000　Hz　to　2800　Hz.　Compared　with　a　structure　of　the　same　size　but　without　considering　the　acoustic　critical　absorption　effect,　the　sound　absorption　performance　of　the　proposed　meta-structure　is　increased　by　30　%.　The　high　agreement　between　finite　element　simulations　and　experimental　results　verifies　the　reliability　of　the　conclusions.　This　work　provides　a　potential　avenue　for　enhancing　noise　reduction　performance　and　reducing　the　dimension　of　the　structures.　©　2022　Elsevier　Ltd