Factors such as crustal movement and land subsidence will cause changes in the tower foundation, which seriously affect the safety of transmission line operation. Taking a 500kV dangerous tower as an example, this article establishes a precise tower-line system which based on finite element method. By simulating the stress distribution of the tower in actual foundation settlement, it can determine the weak components of the settlement tower, and install the strain monitoring system. Combined with the finite element simulation results in various conditions, the reliability of simulation results is verified, and the range of strain variation of the corresponding measuring point is obtained. Then the failure of the tower can be predicted in real time according to the system monitoring results. Combined with the actual engineering application, it has a certain guiding role in judging the stability of the tower under the foundation settlement condition.