The emergence of antimicrobial resistance in bacteria, especially in agents associated with urinary tract infections (UTIs), has initiated an exciting effort to develop biocompatible nanoparticles to confront their threat. Designing simple, cheap, biocompatible, and efficient nanomaterials as bactericidal agents seems to be a judicious response to this problem. Here, a solvothermal method was hired for the one-pot preparation of the cellulose gum (carboxymethyl cellulose, CMC) magnetic composite to prepare a cost-effective, efficient, and biocompatible support for the plant-based stabilization of the silver NPs. The green stabilization of the Ag NPs is performed using Euphorbia plant extract with high efficiency. Various characterization methods, including FT-IR, XRD, SEM, EDS, TEM, and VSM were used to study the composition and properties of Fe3O4@CMC/AgNPs. The composite shows well integrity and monodispersity with a mean diameter of <300 nm, indicating its potential for bio-related application. The CMC functionalities of the proposed material facilitated the stabilization of the Ag NPs, resulting in their monodispersity and enhanced performance. The manufactured composite was used as an antibacterial agent for the removal of UTIs agents, collected from 200 hospitalized patients with acute coronary syndrome, which showed promising results. This study showed that the concentration of the Ag NPs has a direct relationship with the antibacterial properties of the composite.