The invention relates to a traditional Chinese medicine decocting liquid for preventing and treating livestock and poultry parasitic diseases, and a preparation method thereof, wherein the traditionalChinese medicine decocting liquid comprises, by weight, 5-10 parts of cortex meliae, 10-15 parts of artemisia annua l, 5-10 parts of betel nut, 10-15 parts of garlic, 10-15 parts of stemona japonica,5-10 parts of portulaca oleracea l, 10-15 parts of dried tangerine peel, 5-10 parts of cyrtomium fortunei, 10-15 parts of pumpkin seed, 10-15 parts of sophora flavescens ait, 5-10 parts of rheum palmatum l, and 10-15 parts of licorice root. According to the present invention, the traditional Chinese medicine decocting liquid is based on the multiple target points, contains a variety of effectivecomponents, acts in a variety of effective ways, and kills by destroying various living environments of parasites, and the parasites are excreted by supplementing a purgation drug; and the traditionalChinese medicine decocting liquid has advantages of no drug residue, no toxic-side effect, less drug resistance, good safety, easy use and easy absorption, meets the requirements of safe veterinary drugs and animal source food safety ensuring, and is the ideal traditional Chinese medicine decocting liquid for preventing and treating livestock and poultry parasitic diseases.