The invention relates to a method for preparing tirofiban hydrochloride. The method adopts N-butyl sulfonyl-L-imidate and 3-butyne-1-alcohol as starting materials, condensation reaction is carried outto obtain O-3-alkynylbutyl-N-butyl sulfonyl-L-complex amino acid ester and the product is subjected to Sonogashira coupling reaction with 4-halogenated pyridine to obtain N-butyl sulfonyl-O-(4-(pyridine-4-goup)3-butyne-1-group)-L-complex amino acid ester. The preparation of the tirofiban hydrochloride is then completed through hydrogenation reaction and hydrochloric acid salifying.