The invention discloses lactobacillus plantarum and application thereof in preparation of miscanthus sinensis silage, and belongs to the field of microorganisms. The lactobacillus plantarum EC018 is obtained by conducting heavy ion mutagenesis on ordinary lactobacillus plantarum and reserved in Chinese common microbe bacterial preservation administration center on October 8th, 2018, and the preservation number is CGMCC NO. 16556. The lactobacillus plantarum EC018 and lactobacillus casei are mixed according to the bacterial population ratio of 1:1 and sprayed on surfaces of miscanthus sinensissegments so that the pH value of the miscanthus sinensis silage can be reduced, the content of soluble carbohydrates and the content of proteins in the miscanthus sinensis silage after fermentation are increased, the ammoniacal nitrogen content is reduced, degradation of the proteins in the miscanthus sinensis silage is avoided, the content of neutral detergent fibers and the content of acid detergent fibers in the miscanthus sinensis silage are reduced, the nutrition quality and feeding value of the miscanthus sinensis silage are improved; meanwhile, the content of organic acid in the miscanthus sinensis silage is increased, the palatability of the miscanthus sinensis silage is improved, and thus miscanthus sinensis becomes available silage.