NOVELTY - Fasudil hydrochloride is prepared by reacting isoquinoline-5-sulfonic acid with thionyl chloride in N,N-dimethylformamide for 4-8 hours to obtain isoquinoline-5-sulfonyl chloride hydrochloride; adding isoquinoline-5-sulfonyl chloride hydrochloride and sodium bicarbonate in methylene dichloride and water mixed solvent at low temperature and layering to obtain isoquinoline-5-sulfonyl chloride; reacting isoquinoline-5-sulfonyl chloride with homopiperazine in dichloromethane; and recrystallizing fasudil hydrochloride crude product with methanol and ethyl acetate mixed solvent.    USE - Method of preparing fasudil hydrochloride (claimed).    ADVANTAGE - The method is simple and suitable for industrial production, eliminates silica gel column chromatography purification, excess thionyl chloride is removed and reduces enviromental pollution and has high yield and controllable product quality. The obtained product is low in impurity.    DETAILED DESCRIPTION - Preparation of fasudil hydrochloride comprises:    (A) refluxing and reacting isoquinoline-5-sulfonic acid with thionyl chloride in N,N-dimethylformamide catalyst for 4-8 hours, then decompressing and distilling unreacted thionyl chloride, adding dichloromethane and stirring, filtering, decompressing and drying to obtain isoquinoline-5-sulfonyl chloride hydrochloride;    (B) adding isoquinoline-5-sulfonyl chloride hydrochloride and sodium bicarbonate in methylene dichloride and water mixed solvent at low temperature, adjusting pH value to 6-7, standing and layering to obtain isoquinoline-5-sulfonyl chloride in methylene chloride solution;    (C) taking dichloromethane as solvent, reacting isoquinoline-5-sulfonyl chloride with homopiperazine at low temperature, neutralizing using alkali, washing with water, performing acid extraction, adding water-miscible organic solvent and cooling to crystallize, and filtering to obtain fasudil hydrochloride crude product; and    (D) adding fasudil hydrochloride crude product with methanol and ethyl acetate mixed solvent and recrystallizing to obtain the fasudil hydrochloride having purity of more than 99.95%.