Abstract In this study, a porous composite foam with excellent adsorption property toward Pb 2+ was obtained by combining modified polyester (PET) fabric with polyurethane (PU) foam and using melamine and bentonite as modifiers. The effects of bentonite content on the adsorption and mechanical property of the modified fabric were studied. Based on the position of the modified PET fabric in porous PU foam, the P‐PU and PU‐P‐PU composite foams are prepared, and the effects of the fabric‐foam interface structure on the mechanical properties and adsorption properties were investigated. Effects of different experimental conditions such as pH value, contact time and initial dye concentration on adsorption capacity were investigated, and kinetic and isotherm of adsorption were used to analyze the adsorption mechanism of Pb 2+ by foam. It was found that the porous composite foam have outstanding mechanical property and high adsorption efficiency. The adsorption was well‐described by pseudo‐second‐order kinetic and Langmuir isotherm models. Thus, the porous composite foam has great promise in removing heavy metal ions from water.