Abstract: Temperature is an important parameter reflecting the operation status of dry-type transformer. Accurate and fast simulation of temperature field is important for improving the operational reliability of dry-type transformers. The numerical thermal model can accurately simulate the temperature field distribution, whereas the low simulation efficiency of the numerical thermal model is difficult to meet the requirements of operation. Therefore, according to the periodic distribution characteristics of the windings, a fast simulation method for the temperature field of a dry-type transformer based on the equivalent thermal parameters of the windings is proposed to improve the simulation speed of the numerical thermal model. The representative volume element of the periodic structure of the winding is selected, and its anisotropic equivalent thermal conductivity (ETC) is calculated by using the finite element method and Fourier's law. The equivalent density (ED) and equivalent specific heat capacity (ESHC) are derived from the internal composition and material parameters of the representative volume element of the windings. A reduced thermal model of a dry-type transformer is developed based on the above equivalent thermal parameters. A full thermal model is developed by accurately considering the winding conductor and insulation structure. The same computer is used to perform simulations for both the reduced thermal model and the full thermal model. The results show that the distribution characteristics of the temperature field simulated by the reduced thermal model and the full thermal model are all consistent, as well as the velocity field; the calculation errors of the hot spot temperatures are kept within the range of ±4 K; under the condition of the same maximum mesh size, the simulation speed of the reduced thermal model is 193 times that of the full thermal model. The effectiveness of the proposed fast simulation method for temperature field of dry-type transformers based on winding equivalent thermal parameters is verified.