Abstract: Disclosed is a method of preparing an antimicrobial 3D-printing filament, comprising: providing a first mixture comprising a plastic resin and at least one antimicrobial agent selected from the group consisting of an inorganic antimicrobial agent, an organic antimicrobial agent, a metal antimicrobial agent, an ammonium salt antimicrobial agent, a guanidine antimicrobial agent, a copper compound antimicrobial agent, a sustained-release polymer antimicrobial agent, and a natural antimicrobial agent; providing a master batch by extruding the first mixture; and preparing an antimicrobial filament by excluding a second mixture containing the master batch and the plastic resin.