The invention relates to durable antibacterial water-based acrylic resin, which is prepared from an acrylic acid soft monomer, an acrylic acid hard monomer, a schiff base acrylic acid monomer, acrylicacid, azodiisobutyronitrile, a hydroxyl acrylate monomer, an emulgator, a neutralizer and deionized water through reaction, wherein the schiff base acrylic acid monomer is prepared from salicylaldehyde, R-NH2 and acryloyl chloride through reaction. The invention also provides a preparation method of the durable antibacterial water-based acrylic resin. The durable antibacterial water-based acrylicresin prepared through the method has a favorable adhesive force, high gloss, corrosion resistance and the like, and a high performance cost ratio and wide applicability are achieved; when being usedas an antibacterial coating, the durable antibacterial water-based acrylic resin does not need to add an antibacterial agent, can achieve the effects of lastingly resisting and inhibiting bacteria, and can be used as interior and exterior wall coatings, water-based wood coatings, water-based industrial coatings and the like.