Purification method of memantine hydrochloride

The invention provides a purification method of memantine hydrochloride. The method includes: adding a memantine hydrochloride crude product into a mixed solvent of acetone/water, tetrahydrofuran/water, methanol/methyl tert-butyl ether or ethanol/methyl tert-butyl ether, conducting stirring and heating reflux until the solution is clarified, performing cooling to a temperature ranging from -15DEG C to 5DEG C, conducting crystallization for 2-3h, then carrying out filtering, washing and vacuum drying, thus obtaining the memantine hydrochloride with purity of greater than 99.9% and biggest single impurity of less than 0.1%. The method provided by the invention has the characteristics of simple operation and mild conditions, the obtained product has high purity, the impurities meet the quality control requirements, and the product is stable, thus providing reliable guarantee for improving the quality of memantine hydrochloride.