In this paper, topology optimization method is used to optimize the structure of basin-type insulators. The multi-physical finite element simulation model of the basin-type insulators was constructed by COMSOL software. The total elastic strain energy is taken as the optimization objective, the virtual material density inside the structure is taken as the optimization variable, and the constraints such as the material dosage and the upper limit of the maximum electric field are combined to optimize the design of the macrostructure of the basin-type insulator. By analyzing the effects of the material dosage and the upper limit of dielectric constant on the topology optimization results, insulator topologies with uniform electric field distribution and excellent mechanical properties are obtained. The construction method does not rely on the prior information of the geometric structure of the insulator, which provides a new research perspective for the design and optimization of the basin-type insulators.