The invention discloses a preparation method for traditional Chinese medicine bombyx batryticatus. The method comprises the following steps: selection of 5th-instar bombyx batryticatus, preparation for inoculation environment, preparation of bacterial powder, preparation of bacterial liquid, activation of bacterial strains, spraying inoculation, inoculation strengthening and collection and storageof bombyx batryticatus, wherein preparation of the bacterial powder specifically comprises the step of mixing beauveria bassiana strains and diatomite powder granules into bacterial powder granules;preparation of the bacterial liquid specifically comprises the step of adding the bacterial powder granules to purified water for soaking and uniform mixing, filtering a mixed solution, and performingdilution to prepare the bacterial liquid; activation of the bacterial strains specifically comprises the step of adding a proper amount of amino acid and glucose to the bacterial liquid, then placingthe mixture into an activation chamber for activation, adding the activated bacterial liquid to a sprayer to spray to and inoculate the selected 5th-instar bombyx batryticatus, performing feeding with fresh mulberry leaves, performing one intensified inoculation with the bacterial powder granules, regularly observing and collecting stiff bombyx batryticatus, and performing drying, sterilizing andstoring. The preparation method has the characteristics that activity is high, pollution is avoided, and the stiff rate of bombyx batryticatus is high.