The invention relates to the technical field of strain preservation, in particular to a bacterium preservation culture medium and a preparation method thereof. The culture medium comprises the following components: based on 1000ml of the culture medium, 8 to 13 g of 
beef extract, 2 to 6 g of peptone, 0.2 to 0.5 g of cholate, 0.2 to 0.3 g of 
aluminum potassium sulfate, 2 to 5 g of malt extract 
powder, 3 to 7 g of 
yeast extract 
powder, 0.3 to 0.6 g of 
sodium chloride, 5 to 10 g of 
agar, 0.2 to 0.5 g of soluble 
ferric salt, 0.01 to 0.05 g of a 
calcium supplement, 0.02 to 0.05 g of D-
cycloserine, 0.001 to 0.004 g of argentein, 0.01 to 0.02 g of 
vitamin K1, 0.1 to 0.3 g of 
casein phosphopeptides, 3 to 5 g of glucose, 1 to 2.5 g of 
lanthanum nitrate, 3 to 5 g of 
erythritol, 18 to 23 ml of glycerin, 0.1 to 0.2 mg of 
warfarin sodium tablets, 8 to 12 mg of isoniazide, and 75 to 85 ml of sterile defiberized 
sheep blood. The formula of the culture medium is rich and comprehensive in 
nutrient substances, the survival of the strain can be ensured, and the culture medium can still ensure the effectiveness of the strain even if the preservation environment temperature is greatly changed.