We report a simple, fast, and green method to produce gold nanoparticles (AuNPs) that are reduced and stabilized by sodium squarate in water and easily attach to cellulose fibers. The AuNPs and its nanocomposites with cellulose fibers exhibited excellent catalytic activity for the reduction of 4-nitrophenol (4-NP) with NaBH₄. A glass column was packed with the nanocomposites and used for the continuous catalytic reduction of 4-NP with NaBH₄ and demonstrated to be used multiple times (20×) without loss of catalytic activity.