Disclosed is a method of continuously preparing N,N-Bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexamethylenediamine, which relates to chemical engineering. The Pt/C catalyst and the quartz sand are mixed uniformly and loaded to the continuous-flow fixed-bed reactor. Then, hydrogen gas and a substrate solution containing 2,2,6,6-tetramethyl-4-piperidinone and 1,6-hexanediamine are simultaneously fed to the micro-mixer and the continuous-flow fixed-bed reactor in sequence to undergo a continuous catalytic reductive amination to obtain the N,N-Bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexamethylenediamine.