The banana pseudostem fiber was modified by steam explosion and cellulose xanthogenation methods to enhance the capacity of absorbing heavy metal ions Pb2+and Cd2+. The surface morphologies of the steam exploded (SEBF) and cellulose xanthogenate (SEBF‐CX) modified fibers were in loose form and had more surface area. The intensity of –CH, CO, CC, or COC group in SEBF or SEBF‐CX was lower due to hemicellulose and lignin were reduced after the modification, while the cellulose crystallinity and thermal stability were increased based on X‐ray diffraction and thermal analysis. SEBF had higher adsorption capacity at Pb2+concentration below 100 mg/L. However, SEBF‐CX exhibited higher capacity at high concentration of Pb2+. SEBF‐CX had higher adsorption capacity of removing Cd2+as well. The adsorption kinetic of SEBF‐CX was fit to the pseudo second‐order. In general, SEBF‐CX could be used as an economical and efficient absorbent for removing heavy metal ion pollutes in water. POLYM. COMPOS., 39:1869–1877, 2018. © 2016 Society of Plastics Engineers