The invention provides a method for preparing 3-aminomethyl-3,5,5-trimethyl cyclohexylamine. The method includes: a) reacting 3-cyano-3,5,5-trimethyl cyclohexanone with excess primary amine, while removing water of the reaction, so that IPN is substantially completely converted to an imine compound; b) in the presence of an aminolysis catalyst, mixing the resulting product from step a) with liquid ammonia so as to carry out the aminolysis reaction on the imine compound to form 3-cyano-3,5,5-trimethyl cyclohexylimine and the primary amine; and c) performing the hydrogenation reaction to 3-cyano-3,5,5-trimethyl cyclohexylimine obtained in step b) to get 3-carbamoylyl-3,5,5-trimethyl cyclohexylamine in the presence of hydrogen and a hydrogenation catalyst. The method of the present invention prevents the generation of major byproducts of 3,5,5-trimethyl cyclohexanol, and 3-aminomethyl-3,5,5-trimethyl cyclohexanol in the prior art, thereby improving the yield of 3-aminomethyl-3,5,5-trimethyl cyclohexylamine.