Abstract: In order to solve the problems of slow speed and fixed model parameters for solving windings' electromagnetic force (WEF) by traditional finite element method, this paper proposes to apply the response surface fitting calculation method to the calculation of transformer WEF to realize the fast calculation and analysis of transformer WEF under different operating conditions of windings current, and to consider the effect of the radial deformation of the windings on its electromagnetic force. First, the parametric modeling and field circuit coupling analysis of a three-phase transformer are carried out through the finite element software, and the specific distribution of the windings current, magnetic leakage and WEF of the transformer is obtained. Then, the reliability of the model developed in this paper is verified through the experimental design for electromagnetic force measurement, and the leakage and electromagnetic force distribution calculated by simulation and measured are compared by experiment. Finally, the response surface design of windings' electromagnetic force is carried out by combining the design of experiments (DOE) and the Latin hypercube sampling, the fitting relationship between the windings radial and axial electromagnetic force and the windings deformation and windings current under specific laws is constructed, and thus the accuracy of the response surface calculation is verified. This method can provide technical reference for improving the impact resistance of power transformer windings and digital analysis of power equipment.