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, comprising building an electromagnetic analytical model for an electric machine, the solution domain of the analytical model is at least divided into a permanent magnet sub-domain (SD-1), an air gap sub-domain (SD-2), and a stator slot sub-domain (SD-3), and calculating the current magnetic field distributions of the air gap sub-domain (SD-2), the stator slot sub-domain (SD-3) and the permanent magnet sub-domain (SD-1) on basis of a sub-domain method through a Poisson equation or a Laplace equation; wherein the sub-domain method is carried out for any of the sub-domains taken as a target sub domain; the method being characterized by: adding an equivalent current sheet to the boundary of the target sub-domain and to an interface between the target sub-domain and an adjacent sub-domain respectively, using current density of the equivalent current sheet to represent the boundary condition and interface condition, and calculating the magnetic field distribution by the sub-domain method; calculating the magnetic potential difference of each part of the core by a magnetic circuit method according to the current magnetic field distribution, and converting the magnetic potential difference to a current density of the equivalent current sheet; iterating the magnetic field distribution obtained by the sub-domain method and the current density obtained by the magnetic circuit method until a convergent current density is obtained, solving and obtaining the magnetic field distribution of the target sub-domain by using the convergent current density; on basis of the magnetic field distribution, calculating the electromagnetic performance parameters, wherein standard electromagnetic performance parameters are prestored in the processer or the controller, the processer or the controller comparing the calculated electromagnetic performance parameters with the standard electromagnetic performance parameters, and obtaining a evaluating result of the electromagnetic performance. building an electromagnetic analytical model for an electric machine, the solution domain of the analytical model is at least divided into a permanent magnet sub-domain (SD-1), an air gap sub-domain (SD-2), and a stator slot sub-domain (SD-3), and calculating the current magnetic field distributions of the air gap sub-domain (SD-2), the stator slot sub-domain (SD-3) and the permanent magnet sub-domain (SD-1) on basis of a sub-domain method through a Poisson equation or a Laplace equation; wherein the sub-domain method is carried out for any of the sub-domains taken as a target sub domain; the method being characterized by: adding an equivalent current sheet to the boundary of the target sub-domain and to an interface between the target sub-domain and an adjacent sub-domain respectively, using current density of the equivalent current sheet to represent the boundary condition and interface condition, and calculating the magnetic field distribution by the sub-domain method; calculating the magnetic potential difference of each part of the core by a magnetic circuit method according to the current magnetic field distribution, and converting the magnetic potential difference to a current density of the equivalent current sheet; iterating the magnetic field distribution obtained by the sub-domain method and the current density obtained by the magnetic circuit method until a convergent current density is obtained, solving and obtaining the magnetic field distribution of the target sub-domain by using the convergent current density; on basis of the magnetic field distribution, calculating the electromagnetic performance parameters, wherein standard electromagnetic performance parameters are prestored in the processer or the controller, the processer or the controller comparing the calculated electromagnetic performance parameters with the standard electromagnetic performance parameters, and obtaining a evaluating result of the electromagnetic performance. adding an equivalent current sheet to the boundary of the target sub-domain and to an interface between the target sub-domain and an adjacent sub-domain respectively, using current density of the equivalent current sheet to represent the boundary condition and interface condition, and calculating the magnetic field distribution by the sub-domain method; calculating the magnetic potential difference of each part of the core by a magnetic circuit method according to the current magnetic field distribution, and converting the magnetic potential difference to a current density of the equivalent current sheet; iterating the magnetic field distribution obtained by the sub-domain method and the current density obtained by the magnetic circuit method until a convergent current density is obtained, solving and obtaining the magnetic field distribution of the target sub-domain by using the convergent current density; on basis of the magnetic field distribution, calculating the electromagnetic performance parameters, wherein standard electromagnetic performance parameters are prestored in the processer or the controller, the processer or the controller comparing the calculated electromagnetic performance parameters with the standard electromagnetic performance parameters, and obtaining a evaluating result of the electromagnetic performance.