The present invention relates to heat-killed Lactobacillus rhamnosus conjugated to a polysaccharide polymer binder, a preparation method therefor and a use thereof. The heat-killed Lactobacillus rhamnosus conjugated to a polysaccharide polymer binder of the present invention has an excellent therapeutic effect for atopic diseases, and particularly has high industrial applicability because membrane adhesion competitiveness, which is an advantage of existing lactic acid bacteria, is significantly improved, thereby exhibiting dermatitis preventing, alleviating and treating effects of the same level as steroid-based drugs.