The invention relates to a folding circular saw. The folding circular saw comprises a bracket, a work bench, a working bench bracket, a circular saw blade and a motor, wherein the bracket consists of a movable bracket, a fixed bracket and a supporting plate; the upper end of the movable bracket is hinged with the upper end of the fixed bracket; the supporting plate is movably arranged between themovable bracket and the lower part of the fixed bracket to form a triangular supporting structure; and the lower end of the fixed bracket is also provided with a pair of lifting ground wheels througha supporting rod, a connecting rod and a wheel shaft. The folding circular saw has the characteristics of rational structure, reliable supporting and fixing in work and capability of folding the movable bracket in the fixed bracket during transportation, reducing the storage space and reducing the transport cost. When the folding circular saw is assembled for use, the folding circular saw is simple and convenient to install and reset and the working components such as the circular saw blade, the work bench, the work bench bracket and the like do not need to be assembled and debugged, so that the outgoing quality of the machine is ensured. Thus the folding circular saw is particularly suitable for the saw cutting work of round timbers of small-sized timber factories and households.