The invention discloses a preparation method of 1, 3-dimethyl-pentylaminehydrochloride. The preparation method comprises the following steps: performing condensation and dehydration on 2-methylbutyraldehyde used a starting material and nitroethane under the catalyzing of an acetic acid/ ethylenediamine composite catalyst in a methylbenzene solvent to obtain a nitroolefin compound; reducing through potassium borohydride or sodium borohydride; then reducing through palladium carbon and acidizing through hydrochloric acid to obtain 1, 3-dimethyl-pentylaminehydrochloride. The preparation method of 1, 3-dimethyl-pentylaminehydrochloride has the advantages that the raw materials are simple and easy to obtain; the reaction condition is mild; the total yield is high; the industrial production can be performed well.