The invention discloses a drug for curing contagious pleuropneumonia and a preparation method thereof. The drug comprises the following raw crude drugs: magnolia bark, vernonia cinerea, oviductus ranae, peppergrass, scutellaria root, goldthread root, humble plant, conyzae herba, rhodiola root, bamboo shavings, rice distillate, common reed rhizome, semen raphani, Japanese raspberry root, mezoneuron, small fruit fig aerial root, head stephania root, lycoperdales, castanea seguinii and thermopsis lanceolata. The drug has the benefits that the drug takes heat clearing, fire purging, antisepsis, anti-inflammation, lung nourishing, yin nourishing, and cough and asthma relieving as therapeutic principles, has a good curative effect on curing contagious pleuropneumonia, is quick to become effective, has small toxic and side effects, and is low in cost.