The invention discloses a frequency-division multiplexing (FDM)-based three-dimensional (3D) printer, comprising a frame, a base, an X-axis mobile system, a Z-axis mobile system and a printing device, wherein the printing device is connected with the X-axis mobile system; the X-axis mobile system is connected with the Z-axis mobile system; the Z-axis mobile system is connected with a guide rail of an upright post; a power supply and a controller are arranged on the base; the controller is connected with the Z-axis mobile system; the Z-axis mobile system comprises a third numerical control motor, a left screw and a right screw, a Z-axis fixed base and a limit switch; the left screw and the right screw are respectively arranged at the outer sides of a left upright post and a right upright post; the third numerical control motor is connected with the lower ends of the screws; the screws are connected with screw nuts; the screw nuts are connected with the Z-axis fixed base; the Z-axis fixed base is connected with the X-axis mobile system; a fixed base through hole is formed in the Z-axis fixed base; the left upright post and the right upright post pass through the fixed base through hole; the bearing is matched with the guide rail of the upright post. Thus, the FDM-based 3D printer is simple and compact in structure, small in volume and low in manufacturing cost.