The invention discloses a portable mobile 3D printer. The portable mobile 3D printer comprises a material storage device, a shell, a transmission device, a discharging device, a printing bench, a control box, a control device and a power supply, and the transmission device has a three-axis coordinated transmission structure, and comprises an X-axis transmission mechanism, a Y-axis transmission mechanism and a Z-axis transmission mechanism, wherein the X-axis transmission mechanism and the Y-axis transmission mechanism adopt synchronous belt transmission, and the Z-axis transmission mechanism adopts ball screw transmission. The assemblies of the portable mobile small 3D printer have ingeniously designed support structures, so the printer has an extreme compact structure, and the portable mobile design is realized when applicable to ensure the printing dimension; and the portable mobile 3D printer also has the greatly effective door lock mechanism with a simple structure, and has a humanized electricity quantity display design, so the user experience satisfaction is greatly improved, and the printer has very strong market promotion.