The invention provides a continuous preparation method of 3-aminomethyl-3,5,5-trimethylcyclohexylamine. In the invention, a 3-cyan-3,5,5-trimethylcyclohexylimine charging flow reacts with NH3 and hydrogen in the presence of a hydrogenation catalyst. The method is characterized in that the method concretely comprises the following steps: adding an alkaline compound to the 3-cyan-3,5,5-trimethylcyclohexylimine charging flow, and adding an acidic compound to a reaction flow after partial 3-cyan-3,5,5-trimethylcyclohexylimine has been reacted in order to carry out a hydrogenation reaction to prepare the 3-aminomethyl-3,5,5-trimethylcyclohexylamine. The method has the advantages of low amino nitrile content in the product, effective reduction of the reaction stay time, and substantial reduction of the application amount of the catalyst in the hydrogenation reaction process.