The invention discloses a special correction device for a gas-injection boiler drum. The special correction device for the gas-injection boiler drum is characterized by comprising an underframe, a hydraulic cylinder, vertical columns, hydraulic mandrels, mandrel guide pipes, motors, a rolling shaft and a barrel-shaped support seat, wherein the underframe, the vertical columns and the barrel-shaped support seat are comprised; the rolling shaft is arranged at the central position of the barrel-shaped support seat, and the barrel-shaped support seat is in transmission connection with the motors arranged at the two ends of the barrel-shaped support seat through the rolling shaft; the motors are fixedly installed on the vertical columns at the two ends of the barrel-shaped support seat arranged on the underframe; the plurality of mandrel guide pipes are arranged on the barrel-shaped support seat; the plurality of hydraulic mandrels are arranged on the base; the positions of the hydraulic mandrels face the mandrel guide pipes on the barrel-shaped support seat; and each mandrel guide pipe is provided with seven mandrel guide pipe stations. The special correction device for the gas-injection boiler drum, which is disclosed by the invention, has the advantages of being simple in structure, reasonable in design, convenient to operate, time-saving and labour-saving, high in working efficiency, flexible to adjust, capable of lowering the labour intensity of personnel, and adaptive to correction for a drum body with large diameter and length of a gas-injection boiler.