Taking the T-shaped LW15A-363/Y high-voltage circuit breaker structure as the prototype, based on the similarity theory, an experimental model with 1:4.5 reduced-scale is designed and constructed. El Centro wave, Lanzhou wave and Chi-Chi wave are adapted as the ground motion input, respectively along the X and Y axial to the model, the simulated earthquake shaking table test is carried out under different peak ground acceleration (PGA). The seismic response law of the model is studied in the weak parts such as the root of the insulating porcelain column, the top and root of the equipment. In addition, C3D8R element is used for porcelain column and S8R element for flange. ABAQUS finite element model of model structure is established by sweeping mesh division method, and the dynamic response at El Centro wave under X direction excitation is analyzed. Results show that there is a large stiffness difference between inside plane and outside plane of T-shaped high-voltage circuit breaker for single axial symmetry structure, so the dynamic response of structure model under seismic excitation in the Y direction is greater than the X direction; and the seismic response at the end of the insulated porcelain column in the Y direction is the largest and the acceleration amplification coefficient is from 1.1 to 2.2. Between the finite element analysis and the test, the maximum error of natural vibration frequency is 13.2%, the maximum error of acceleration response peak is 9.2% and the maximum error of the displacement response peak is 14.3%, so the two fit well. The research can provide reference for seismic design and engineering application of such circuit breaker structures.