Disclosed herein is a novel method for preparing lercanidipine hydrochloride which is highly effective for treating hypertension. The method comprises the steps of reacting 2,6-dimethyl-5-methoxycarbonyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3-carboxylic acid with a substituted chlorophosphate derivative to obtain a substituted phosphonoester derivative, and reacting the substituted phosphonoester derivative with 2, N-dimethyl-N-(3,3-diphenylpropyl)-1-amino-2-propanol. According to the preparation method, since little by-products are formed, the yield is improved, as compared to cases of conventional methods. In addition, the method involves simple isolation and purification processes of lercanidipine, thus realizing a high-quality product. Furthermore, the method has advantages of low preparation costs, substantial waste-free environmental-friendly process and applicability to industrial mass-production.