The invention pertains to the field of biological transformation technology, which relates to a preparation method and the usage of
fermentation liquid and
fermentation liquid extract of
ginkgo biloba leaf transformed by
hericium erinaceus. The invention inoculates the
hericium erinaceus in a wheat
bran solid culture medium to be cultured respectively for 3 to 7 days, after that, the mixture is firstly trans-inoculated in a seed culture medium to be cultured for 1 to 2 days and is finally trans-inoculated in a
fermentation culture medium to be cultured, wherein, the seed culture medium composition is: 10 to 40g / L of glucose, 1 to 5g / L of wheat
bran, 2 to 10g / L of peptone and 5 to 20g / L of
corn flour; the fermentation culture medium is: 10 to 40g / L of glucose, 1 to 5g / L of wheat
bran, 2 to 10g / L of peptone, 5 to 20g / L of
corn flour, 0 to 1g / L of MgSO4.7H2O, 0.1 to 2g / L of KH2PO4, 1 to 10g / L of CaCO3 and 0.2 to 5 percent EGB. The method of the invention has low cost, simple process, convenient management and can save manpower and
material resources; furthermore, the tests for rats with diabetes prove that the prepared fermentation liquid can be used in the preparation of the drugs for lowering blood glucose.