The invention belongs to the filed of processing of agricultural products and in particular relates to a mixed powder containing an enoki mushroom powder and a preparation method thereof. The mixed powder is obtained through evenly mixing the following components in parts by weight: 10-20 parts of enoki mushroom powder, 10-20 parts of millet powder, 10-20 parts of corn powder, 5-20 parts of soybean meal, and 70-80 parts of wheat meal. The mixed powder containing the enoki mushroom powder is prepared from the raw materials in proportion, the enoki mushroom powder is added into the mixed powder, and the enoki mushroom powder is rich in trace element selenium, thus the product in the invention has the advantages of antioxidation, tumour resistance and effect on improving the organism immunity. According to the invention, the wheat meal, the corn powder and the soybean meal are reasonably matched to reflect extractive refined grains and fine coarse grains, and the nutritions of the refined grains and the coarse grains are complementary mutually.