In order to study the temperature distribution characteristics of the whole and inner layer winding of dry-type air-core reactor, a three dimensional temperature rise calculation model of electromagnetic-fluid-temperature of dry-type air-core reactor is established based on the multi physical field coupling method of electromagnetic heat flux. First of all, based on the electromagnetism theory of field-circuit coupling, current of each layer of the reactor was calculated by finite element method and the winding loss of each layer is calculated. Then, based on the heat transfer theory of fluid-temperature coupling, taking the winding loss of each layer as the heat source, the finite volume method is used to solve the reactor temperature distribution. Finally, the accuracy of the results is verified by the steady-state thermal analysis method. The results show that the temperature distribution of the reactor shows the trend that the upper region is larger than the lower one and the middle enclosure is larger than the two sides. The hot spot temperature rise of each layer is about 85%~90% of the reactor axial height. The research results provide a theoretical basis for the optimization of the reactor structure and the on-line monitoring of the temperature. This work is supported by National Natural Science Foundation of China (No. 51577050) and Key Science and Technology Projects of State Grid Jiangsu Electric Power Co., Ltd. in 2018 (No. J2018014).