The invention belongs to the technical field of lactobacillus culture, and relates to a feeding lactobacillus johnsonii high-density fermentation medium and application thereof. By using the high-density fermentation medium and the lactobacillus johnsonii fermented by a fermentation method for the fermentation medium, the bacterial density is remarkably improved relative to common fermentation, the number of viable bacteria is not less than 1,010cfu/ml and is improved by over 80 times compared with the viable bacteria cultured by a common MRS culture medium, and high-density fermentation of the lactobacillus johnsonii is realized; and according to the fermentation medium and the application thereof, the separation cost of biomass is reduced, the production period is shortened, the production cost is reduced, and the production efficiency is improved.