High-frequency electromagnetic fields can couple to overhead transmission lines. When the wavelength of the high-frequency electromagnetic fields is smaller than the height of the transmission lines, the classical transmission line theory is no longer applicable. Although the traditional full-wave numerical algorithm can solve this problem, the solution is very inefficient, and it needs to consume a lot of time and computational resources. In addition, power system transmission lines often have multiple vertical ends, and the line layout is complex, while previous studies on efficient solutions for power system transmission lines are simple models with only two vertical ends on the left and right, which can not be conformed to the structure of the actual power system transmission lines. In order to solve these problems, a theoretically effective method is proposed in this paper to address the high-frequency electromagnetic fields coupling to multilevel transmission lines of power systems with scatterers. The computationally efficient asymptotic method is used, and the concept of scatterers is introduced into the asymptotic method. Finally, the accuracy and effectiveness of the method are verified by numerical examples.