The invention discloses a transformer vortex field finite element solving method based on a sinc function. According to the method, first, a model is established for a transformer, and then meshing isperformed on the established model according to a finite element method; the finite element method is adopted to calculate a stiffness matrix and a damping matrix of the model according to unit nodeinformation obtained through meshing; and a magnetic vector potential and a scalar potential are selected to serve as an unknown function of a vortex field mathematical model, a discretization formatis exported through a Galerkin finite element method, a discretization equation set is established, solutions of the discretization equation set are solved through a sinc interpolation method, electric field distribution and magnetic field distribution in a transformer solving domain can be obtained according to the solutions of the equation set, and therefore vortex distribution and loss of the transformer can be calculated. The method is simple in design, easy to implement and easy to popularize, provides more precise analysis for vortex field and loss calculation of large and ultra-large power transformers, provides a basis for transformer design and manufacturing and improves the security and stability of transformer operation.