A multifunctional palygorskite/polyaniline/Ag nanoparticles (PAL/PANI/AgNPs) nanocomposite was prepared at room temperature using a simple one-pot in-situ polymerization reaction of aniline monomers triggered by Ag(I) on the surface of natural PAL nanorods. Ag(I) served as both the oxidant and the precursor of the AgNPs, which initiated the polymerization of aniline monomers on PAL nanorods while simultaneously being reduced to form Ag⁰ nanoparticles (AgNPs). The in-situ formed AgNPs were evenly distributed on the surface of the PAL nanorods because the interfacial effect of PAL prevents their aggregation. The density and size of the AgNPs and the catalytic activity of the nanocomposites could be controlled by altering the molar ratio of aniline to Ag(I). The performance evaluation revealed that the nanocomposites could be used as highly active catalysts, which rapidly catalyzed the reduction of 4-nitrophenol (4-NP) within 2 min and Congo red (CR) within 10 min. The nanocomposites are also an effective adsorbent for H₂PO₄⁻ able to remove 99.40% of H₂PO₄⁻ (only 61.77% for raw PAL) from a solution with an initial concentration of 50 mg/L. This multifunctional nanocomposite synthesized by a simple one-pot approach is a promising material for environmental applications.