In this paper, by adding melamine and bentonite to the polyurethane (PU) foam, a porous composite material with heavy metal adsorption properties is obtained. The cell size of the PU porous composite foam was affected by the addition of melamine and bentonite particles. With the increase of particles amount, the cell size decreased. The compression performance of the composite foam increased by 54% after adding 8 wt% melamine particles. The optimal adsorption conditions such as pH, adsorption time, and initial concentration of PU porous composites were also explored. Result shows that porous composite foam had a good removal effect on Pb2+. Moreover, the Langmuir model, the Freundlich model, and the adsorption kinetic model are used to evaluate the adsorption capacity of the porous composite foam. It is of great significance to obtain porous composite with good heavy‐metal adsorption and high‐strength performance.