The invention provides a Chinese medicament for treating colorectal polypus. The Chinese medicament comprises the following raw materials in percentage by weight: 32 to 38 percent of dark plum fruit, 24 to 32 percent of stiff silkworm, 15 to 24 percent of zedoary, 6 to 18 percent of safflower, 1 to 3 percent of human nail and 10 to 18 percent of rice vinegar. The preparation method comprises the following steps of: processing the dark plum fruit and the human nail first during the preparation of the Chinese medicament, and preparing the raw materials into oral administration preparations comprising pills, capsules, granules, tablets and enteric-coated sustained-release preparations according to the standard preparation process of various formulations, wherein the enteric-coated sustained-release preparations comprise sustained-release enteric-coated tablets, enteric-coated capsules, enteric-coated pills, enteric-coated soft capsules and the like. The Chinese medicament has the effect of softening hardness to dissipate stagnation and melting polypus, and can cure various kinds of polypus and particularly colorectal polypus.