The invention particularly relates to a method and a system for drawing a wire corrosion distribution map of an overhead transmission line. The method comprises the steps of obtaining a wire corrosionrate based on collected related data of the overhead transmission line and a pre-constructed corrosion rate calculation formula, and drawing a wire corrosion rate distribution diagram based on the wire corrosion rate, and drawing a revised wire corrosion distribution diagram based on the drawn wire corrosion distribution diagram according to the influence of the wind speed, the wind direction, the terrain and the operation condition on wire corrosion. The invention relates to a method and a system for monitoring the corrosion degree of an overhead transmission line wire. The pre-collected data is substituted into a pre-constructed corrosion rate calculation formula to obtain a wire corrosion rate, a corrosion distribution map is drawn based on the wire corrosion rate, and a corrected corrosion distribution map is drawn according to the influence of the wind speed. The wind direction and the terrain on wire corrosion, so that the method can solve the potential safety hazard of the lineand avoid property loss.