The invention provides a preparation method of a traditional Chinese medicine for treating red urine type acute contagious conjunctivitis, and belongs to the technical field of preparation methods of traditional Chinese medicines. Currently, sulfonamides and antibiotics are generally adopted to treat red urine type acute contagious conjunctivitis, but gastrointestinal reaction, crystalluria, hematuresis, rash, drug fever and leucopenia are caused to a patient who administrates sulfamethoxazole. The preparation method is characterized by comprising the following steps of immersing the following 27 traditional medicines in water, namely coix seed, exocarpium benincasae, rice bean, zanthoxylum bungeanum maxim, corn stigma, calabash, dayflower, polygonum aviculare, dianthus superbus, akebiaquinata, ricepaper pith, rush, patrinia, changium smyrnioides, hemsleya macrosperma, rhizoma anemarrhenae, arrowshaped tinospora root, trollflower, honeysuckle, spanishneedles herb, cordate houttuynia, Japan clover herb, hyperforin perforatum, sedum sarmentosum, common leafflower herb with root, lophatherum gracile and liquorice; decocting with slow fire; and filtering and removing slag to obtain decoction, which is the traditional Chinese medicine for treating red urine type acute contagious conjunctivitis. The Chinese medicine lotion has the advantages of small toxic and side effect of prepared Chinese medicine decoction, short course of treatment and high cure rate.