Method for evaluating electromagnetic performance of a permanent-magnet machine, wherein the method is implemented in a computer processer or in a controller of a permanent-magnet machine, calculating the magnetic field distribution by a sub-domain method; using current density of the equivalent current sheet to represent the boundary condition, iterating by the sub-do-main method and by the magnetic circuit method until a convergent result is obtained, calculating the electro-magnetic performance parameters on basis of the convergent result, so as to evaluate the electromagnetic performance.