The invention discloses an antibacterial micro-nano gel with a protein adsorption function, an antibacterial hydrogel fiber with a protein adsorption function, and preparation methods of the antibacterial micro-nano gel and the antibacterial hydrogel fiber. The preparation methods comprise the following steps: dissolving an acrylic acid or methacrylic acid derivative polymerizable monomer, an ion-based water-soluble polymerizable monomer and a polymerizable antibacterial agent monomer in deionized water, dissolving an epoxy propyl methacrylate polymerizable monomer in dimethyl sulfoxide, uniformly mixing the two solutions, then adding a cross-linking agent and an initiator, and conducting stirring and dissolving to obtain a prepolymer solution; adding tetramethylethylenediamine into the prepolymer solution, conducting standing to form gel, conducting drying and crushing to obtain the antibacterial micro-nano gel; and placing the prepolymer solution in a fibrous template, and carrying out ultraviolet irradiation or template heating initiation to obtain the antibacterial hydrogel fiber. The prepared antibacterial micro-nano gel and hydrogel fiber have excellent water absorption performance, protein adsorption performance and lasting antibacterial performance, are good in biocompatibility and are harmless to the human body.