In order to obtain the thermodynamic effect of the 220kV single-core AC cable under serpentine laying, the finite element analysis method was used for modeling and simulation. According to the field conditions and cable structure characteristics, a two-dimensional model of the cable between two adjacent fixtures was established. The temperature distribution and stress distribution of the cable under the rated current capacity were analyzed by thermomechanical coupling method, and the values were analyzed numerically. The results show that the stress in the free part of the cable is significantly less than the two ends, and the stress of the copper conductor and the aluminum sheath at the end exceeds their yield strength, which is prone to danger. This study provides theoretical and data references for practical laying and routine inspections.