The invention discloses a method for preparing a culture medium for a lichen frozen food base stock. The preparation method comprises: cleaning, drying and crushing gyrophora or thamnolia vermicularis (Ach.) Asahina lichen, inoculating the crushed gyrophora or thamnolia vermicularis (Ach.) Asahina lichen into a culture medium prepared by using starch syrup, Indian meal, yeast extract paste, sucrose, KH2PO4 and the like as main raw materials and culturing the lichen by using a liquid ventilated culture method at normal temperature; and filtering (or then concentrating) the culture medium, and using the resulting product as auxiliary materials for making dumpling wrappers, frozen bread paste, frozen noodles, frozen glue puddings, ice cream, fruit and vegetable products and quick-frozen prepared foods. The method has the advantages of obviously improving the anti-cracking performance of frozen foods, delaying food aging, lowering the freezing point, reducing juice or water loss, improving the elasticity of frozen foods and contributing to the preservation of the quality of the frozen foods.