The invention provides a cordyceps sinensis mycelium with the functions of clearing damp and reducing weight. A preparation method of the cordyceps sinensis mycelium comprises the following steps: preparing a culture medium by adopting semen ormosiae hosiei, coix lacryma-jobi and rhizoma dioscoreae as raw materials, sterilizing the culture medium, inoculating cordyceps sinensis strains into the culture medium, carrying out culturing till hyphae grow on the whole culture medium, airing the culture medium on which the hyphae grow, and carrying out smashing to obtain the cordyceps sinensis mycelium with the function of clearing damp. Due to the implementation of the technical scheme, semen ormosiae hosiei, coix lacryma-jobi, rhizoma dioscoreae and cordyceps sinensis hyphae are assembled to form another special combination, namely, the semen ormosiae hosiei, coix lacryma-jobi, rhizoma dioscoreae and cordyceps sinensis combined mycelium, the combined mycelium has the functions of clearing damp and reducing weight, moreover, the nutrition, function and efficacies of the combined mycelium are prominent, and thus the cordyceps sinensis mycelium has the wide health efficacies. In addition, due to the implementation of the technical scheme, the preparation and preparation process of the semen ormosiae hosiei, coix lacryma-jobi, rhizoma dioscoreae and cordyceps sinensis combined mycelium also has the characteristics of short culture period, simple technology, high production efficiency of products, production stability and the like.