The invention relates to a cutting device, in particular to a fine iron wire cutting device for construction. Therefore, the technical problem of the present invention is to provide a thin iron wire cutting device for construction that can replace manual cutting of thin iron wires, saves more labor, avoids hand soreness affecting follow-up work, and has the same length of cut thin iron wires. The technical embodiment of the present invention is: a thin iron wire cutting device for construction, including a base, a support plate, a first bearing seat, a first rotating shaft, a movable plate, a first guide sleeve, a first guide rod, etc.; There are support plates at the rear of the side. In the present invention, the thin iron wire rolls are fixed on the upper and lower arc-shaped plates, and the first motor is started to rotate forward, so that the head end of the thin iron wire can continuously move to the right, and at the same time, the cutting knife can be moved up and down to move to the right. The moving thin wire is cut off without the need for people to use wire cutters to cut the thin wire, which saves more effort, avoids sore hands, and also makes the length of the cut thin wire consistent.