The invention provides a culture medium capable of improving biological stuffing microbial activity and a preparation method thereof, and relates to the technical field of biological stuffing. The culture medium is characterized by being prepared from, by weight, 100-150 parts of peptone, 80-100 parts of beef extract, 10-20 parts of yeast extract, 20-25 parts of glucose, 5-10 parts of sodium chloride, 20-30 parts of agar, 15-20 parts of bile salt from a pig, 12-18 parts of casein hydrolysate, 7-12 parts of sodium nitrate, 5-8 parts of monopotassium phosphate, 10-12 parts of amino acid and 16-20 parts of enrichment broth. The prepared culture medium allows growing microorganisms to be rich in type, a proper survival environment is provided for the microorganisms, nutritional ingredients (N, P, K and trace elements) are reasonable, the nutritional ingredients needed in the microorganism growth and reproduction processes are met, the microbial activity is greatly improved, the odor treatment effect is good, and the strictest environmental requirement in various regions can be met in any season.