Abstract: When a power transformer is submitted to a short-circuit condition, the short circuit transient current generates a huge force on windings which cause the deformation of windings or even make the insulation and mechanical structure of power transformer breakdown, therefore calculating the force and analyzing its characteristic are helpful to predict the deformation, which also can provide reference to the design of transformer. In this paper 2-D and 3-D models of three-phase transformer is built by finite-element software ANSYS Maxell which are used to calculate the axial and radial electromagnetic forces of windings. The short circuit current results obtained by FEM are compared with the analytical results, they show good agreement, which verify the reliability of FEM model and the simulation method. The results show the axial force on both ends of windings is bigger than that on middle; the radial force on middle of windings is bigger than that on both ends.