Malachite　green　(MG)　is　widely　used　as　a　textile　dye　and　an　aquacultural　biocide,　and　become　a　serious　pollution　of　drink　water,　but　effectually　isolating　and　removing　it　from　wastewater　are　still　a　challenge.　Here　we　report　a　new　strategy　to　prepare　a　carbon　foam　with　tunable　pore　size　distribution　by　a　one-pot　lava　foam　process.　We　find　that　uniform　micropore　size　is　beneficial　to　the　formation　of　C–OH　coordination　on　the　pore　surface,　increasing　MG　adsorption　rates　via　H+　ionization.　As　a　result,　carbon　foam　with　uniform　pore　size　distribution　demonstrates　an　optimum　MG　removal　efficiency　of　1812　mg　g−1　and　a　higher　partition　coefficient　of　3.02　mg　g−1　μM−1,　which　is　twice　that　of　carbon　foams　with　irregular　pore　size　distribution.　The　adsorption　of　MG　onto　these　adsorbents　was　found　to　be　an　endothermic　monolayer　chemical　adsorption　process,　and　the　Gibbs　free　energy　of　adsorption　process　was　decreased　obviously　by　regulating　micropore　size　distribution.　The　experiment　results　are　in　good　agreement　with　pseudo-second-order　kinetic　and　Langmuir　isotherm　models.　Revealed　the　pore　size　distribution　was　the　critical　factor　of　MG　removal　by　carbon　foam.　It　should　be　and　inspiration　for　the　design　and　development　of　highly　efficiency　adsorbents　for　dyes　removal.　©　2022　Elsevier　Inc.