A method for treating the uneven settlement of iron tower leg in collapse area includes such steps as calculating the settlement of four tow foundations of iron tower according to the tower leg with the smallest settlement, and calculating the settlement of the four tower foundations according to the settlement of the tower leg. S2: finite element model of iron tower is established by ANSYS software according to actual size; S3, restraining the rotational displacement and the horizontal displacement of all the tower legs, and calculating the position where the stress value in the finite element model is greater than or close to the design strength of the tower material; 4, adding a foundation reinforcement structure and reinforcing a reinforcement structure on that finite element model; 5,resetting the constraint setting of the foundation node of the pylon leg according to the settlement and the reinforcement; S6: calculating the force of the iron tower again, repeating step S4-S5, until the force on the tower is within the design range. Combined with the finite element model, considering the settlement and reinforcement materials, the method restrains the degree of freedom of thefour tower foundations, and realizes the reinforcement of transmission tower.