The invention provides a portable carbon resistance welding device, and relates to the technical field of welding devices. The portable carbon resistance welding device comprises an accommodating box body. A rectangular through opening is formed in the lower part of the front end face of the accommodating box body, and a shielding assembly is mounted in the position, outside the rectangular through opening, of the front end face of the accommodating box body; and an E-shaped through opening is formed in the right end face of the accommodating box body, an air blowing mechanism is arranged at the position, located at the E-shaped through opening, of the right end face of the accommodating box body, a cleaning part is arranged at the right end of the air blowing mechanism, and a limiting part is installed on the rear end face of the accommodating box body. Through the arrangement of the accommodating box body and a battery assembly, the welding device cannot be limited when being used outdoors; and through arrangement of the shielding assembly, a large number of bolts and other fasteners do not need to be disassembled through tools during maintenance of the welding device, so that the convenience during maintenance of the welding device is improved, and the problems that an existing welding device is limited during field use and is not easy to disassemble during maintenance, and convenience during maintenance is lowered are solved.