The invention discloses an orally-taken drug for treating acute suppurative nasosinusitis and a preparation method thereof, wherein the drug comprises the components in parts by mass: 1-3 parts of radix puerariae, 1-3 parts of rhizoma cimicifugae, 1-3 parts of radix paeoniae rubra, 1-3 parts of raw licorice, 1-3 parts of radix scutellariae, 1-3 parts of dandelion, 1-3 parts of honeysuckle flower, 1-3 parts of rhizoma chuanxiong, 1-3 parts of radix platycodi, and 1-3 parts of radix angelicae. The preparation method of the drug comprises the following steps: according to the mass parts, choosing and buying high-quality and clean radix puerariae, rhizoma cimicifugae, radix paeoniae rubra, raw licorice, radix scutellariae, dandelion, honeysuckle flower, rhizoma chuanxiong, radix platycodi and radix angelicae, respectively picking out impurities and dust, then putting into a cloth bag, and tying; putting the cloth bag full of the drug into a cold boiled water, soaking for half an hour, then together putting the soaked drug and the clarified liquid soaking the drug into a drug-decocting machine, adding a proper amount of cold boiled water, decocting twice, carrying out the first decoction for 50 minutes, filtering and taking a drug solution, again adding lukewarm boiled water, carrying out the second decoction for 40 minutes, merging and concentrating into 1710 ml of a 50% traditional Chinese medicine solution, bagging, and sealing.