The invention provides an application of lactobacillus rhamnosus in regulating immunity. The lactobacillus rhamnosus is preserved in China General Microbiological Culture Collection Center on August 10, 2017, has the preservation number of CGMCC No.14511, and is classified and named as lactobacillus rhamnosus. The lactobacillus rhamnosus has good immunoregulatory effect on a body, has the inhibiting effect on the expression of inflammatory factors, the promotion effect on the anti-inflammatory factors and the promotion effect on lymphocyte proliferation significantly better than those of conventional commercial lactobacillus rhamnosus strains, and has immunoregulatory function on the body significantly better than that of the conventional lactobacillus rhamnosus strains.