The invention relates to a medicine-memantine hydrochloride synthesized from 1-chloro-3,5-dimethyladamantane as an initial raw material. At present, many synthesis methods for preparing memantine hydrochloride, such as urea method, digestive catalytic reduction method, acetamide method and acetonitrile method, have the problems of high bromide / urea reaction temperature, long time, great environmental pollution and the like to different degrees. The invention aims to develop a synthesis technique of the medicine memantine hydrochloride. The technical scheme is as follows: the technique comprises the following steps: by using 1-chloro-3,5-dimethyladamantane as the initial raw material and formamide as an aminating agent, carrying out amination reaction to generate a key intermediate 1-formamido-3,5-dimethyladamantane, hydrolyzing with concentrated hydrochloric acid, salifying, and carrying out vacuum drying to obtain the memantine hydrochloride. The reaction between the formamide and 1-chloro-3,5-dimethyladamantane shortens the reaction time, lowers the reaction temperature, and provides higher product yield and purity (the product yield is higher than 76%, and the purity is higher than 99%).