A method for improving the mechanical property of thread steel comprises the following steps that (1) the included angle alpha of the side faces of transverse ribs and the inner diameter surface of the thread steel is increased; (2) the transverse rib distance l is increased; and (3) the transverse rib height h is reduced. Alpha, l and h are all within the ranges limited by national standards. Thesteps (1), (2) and (3) are in no particular order. The method has the beneficial effects that the mechanical property of the thread steel and the material utilization rate are improved, and the production cost is reduced. The invention belongs to the technical field of thread steel.