The utility model belongs to the technical field of iron-making devices, and particularly relates to an iron-making device convenient to adjust air inlet volume, which comprises a frame, a support ring is fixedly connected in the frame, a support shaft is mounted in the support ring through a bearing, fan blades are fixedly connected to the outer side of the support shaft, and a filter mechanism is arranged in the frame. A supporting plate is welded to the upper end of the frame, a motor is fixedly installed at the right end of the supporting plate, a rotating shaft of the motor penetrates through the supporting plate and is rotationally connected with the supporting plate, a driving wheel is fixedly connected to the left end of the rotating shaft, a belt is arranged on the outer side of the driving wheel, and the belt penetrates through the frame and is slidably connected with the frame. According to the utility model, the screw rod and the screw cylinder are rotated to do threaded motion, so that the support drives the pressing wheel to move, the pressing wheel tensions the belt, the belt is prevented from aging and loosening after long-time use, and the opening and closing effect of the wind shield is ensured.