The invention discloses a medicine for treating pertussis and a preparation method thereof, wherein the medicine is mainly prepared from grasshoppers, herb of diversifolious pimpinella, pig gall, gecko, centipede, rhamnus davurica, azoila imbricata, chimonanthi flos, potentilla fulgens wall, pearlwort, amur lilac, uroctea nest, lemon, pittosporum seed, semiaquilegia adoxoides, rhizoma kaempferiae,luffa vegetable juice, veronica undulata, Chinese osbeckia herb, jade hibiscus, corydalis cheilanthifolia, radix caulophylli, malva verticillata leaves, hydrocotyle nepalensis, herb of comnon thunia,ivy glorybind rhizome, vernonia patula, rungia pectinata, flower of Japanese glorybowe, nutgrass flatsedge, spinach beet, sago seed, arenaria serpyllifolia and male goat horn according to a certain weight ratio. The medicine has the functions of relieving cough and asthma, invigorating lung and kidney, removing stasis and relieving cough and eliminating phlegm, and has quick effect and good curative effect when being used for treatment of pertussis.