NOVELTY - Preparing cefotiam hydrochloride includes adding purified water to the reactor with acetonitrile, adding 7-(2-acetoxycyclopropyltrimethylammonium iodide) (7-ACTM), adding triethylamine to 7-ACTM, dissolving, adding acetylthiocholine chloride (ATC-HCl), reacting, adding an organic solvent and concentrated hydrochloric acid, stirring, cooling, heat stirring, and then adding acetone dropwise again, stirring, suction filtration, recovering the mother liquor, washing the filter cake and drying to obtain crude cefotiam hydrochloride, refining, recycling, and recovering liquor.    USE - Method for preparing cefotiam hydrochloride (claimed).    ADVANTAGE - The method has improved yield of cefotiam hydrochloride. The quality of the product meets the standard.    DETAILED DESCRIPTION - Preparing cefotiam hydrochloride comprises:    (A) adding purified water to the reactor with acetonitrile, adding 7-ACTM, adding triethylamine to 7-ACTM, dissolving, adding ATC-HCl to cooling bath, reacting to obtain 0.8-1% 7-ACTM residue, adding an organic solvent incompatible with water and concentrated hydrochloric acid, and stirring to provide an aqueous phase, adding concentrated hydrochloric acid in the aqueous phase, and adding acetone to the reaction solution, cooling at 4-6 degrees C, heat stirring for 1 hour, and then adding acetone dropwise again, stirring for 3 hours , suction filtration, recovering the mother liquor, washing the filter cake twice with acetone and drying to obtain crude cefotiam hydrochloride ;    (B) dissolving the crude cefotiam hydrochloride with purified water, adding activated carbon, filtering, adding concentrated hydrochloric acid to the filtrate, and then adding acetone to the reaction solution, heat stirring for 1 hour and adding acetone dropwise again, incubating at 0-5 degrees C for 2 hours, suction filtration, and recovering the mother liquor, washing the filter cake with acetone to obtain cefotiam hydrochloride;    (C) using an organic solvent incompatible with water and extracting liquor, and recovering an aqueous phase, i.e., the mother liquor;    (D) adding the recycled mother liquor to the reactor, adding purified water, acetonitrile, and triethylamine to the dissolved 7-ACTM, and then adding the cooling bath to the reaction until the residue of 7-ACTM is 0.8-1%, adding an organic solvent incompatible with water, concentrated hydrochloric acid, followed by stirring static layer and an aqueous phase; successively adding in the aqueous phase recovered mother liquor, adding concentrated hydrochloric acid to acetone, heat stirring at 4-6 degrees C for 1 hour, then again a solution of acetone, stirring at 0-2 degrees C for 3 hours to obtain cultured crystals, suction filtration, recovering the mother liquor, washing the filter cake twice with acetone, drying to obtain crude cefotiam hydrochloride, recycling the mother liquor, and post-treatment stand; and    (E) recycling the mother liquor, dissolving the crude product, adding activated carbon, filtering, concentrating, adding hydrochloric acid to the filtrate, and then adding the acetone to the reaction solution, heat stirring at 6-8 degrees C for 1 hour, then again a solution of acetone after incubating at 0-5 degrees C for 2 hours, suction filtration , and recovering the mother liquor, washing the filter cake with acetone to obtain the cefotiam hydrochloride, and recycling the mother liquor.