The invention relates to a method for preparing cordyceps mycelia through mulberry twig powder and silkworm chrysalis powder. The method comprises the following steps: forming a substrate by the mulberry twig powder and the silkworm chrysalis powder, preparing a nutrient solution without inorganic salts by potatoes, flour and soybean powder, then forming a culture medium for production by the substrate and the nutrient solution, using liquid bacteria species of cordyceps as bacteria species, grasping an inoculation method and the inoculation number of the liquid bacteria species, culturing the cordyceps mycelia by reasonably arranging production environment, and finally, preparing the cordyceps mycelia. Through the implementation of the method disclosed by the invention, the mulberry twig powder, the silkworm chrysalis powder and the cordyceps bacteria species are combined to form another special combination, namely the cordyceps mycelium which is outstanding in nutrition, function and efficacy, and the mycelium can be widely applied to functional tea beverages, wine processed products, special food and the like, so that the value of mulberry twigs is increased by dozens of times. At the same time, the method disclosed by the invention also has the characteristics of short breeding period, simple production and preparation technologies, low production cost of products, high and stable production efficiency of the products, and the like.