The invention relates to a preparation method of a traditional Chinese medicine piece, and in particular relates to a preparation method of a periplaneta americana superfine-grinding granulate piece. The preparation method mainly comprises the steps of fasting, catching and killing, drying, degreasing, superfine grinding, mixing, pelletizing, completely mixing, and packing by quantity, etc. The preparation method has the advantages that any excipient, binding agent and other auxiliary materials are not added, the natural characteristics of the traditional Chinese medicine are kept in a hundred percent, the advantages of the traditional Chinese medicine are remained, and a patient is convenient to take; the process is regular, the parameters are easy to detect and control, and large-scale and mass production is easily carried out; petroleum ether with boiling range of 60 to 90 DEG C is used as a degreasing solvent, which is high in volatility, nontoxic and easy to remove; in addition, petroleum ether is reusable, so that the resource is saved.