Axial flux permanent magnet synchronous motor has the characteristics of short axial length, compact structure, small volume, high torque density, etc. However, its magnetic field is a three-dimensional magnetic field, and the model is too complex to be solved and calculated directly by the classical analytical method. In order to quickly complete the preliminary estimation of the axial flux permanent magnet synchronous motor, a simplified equivalent magnetic circuit model is proposed to quickly calculate the basic performance of the axial flux permanent magnet synchronous motor. The magnetic circuit model transforms the three-dimensional axial flux permanent magnet synchronous motor model into a multi-layer two-dimensional equivalent model through reasonable equivalence, and then uses the equivalent magnetic circuit method and superposition method to calculate the motor performance. Finally, taking a 10 pole 12 slot double stator single rotor axial flux permanent magnet synchronous motor as an example, the model described in the article was used to calculate its air gap magnetic density, permanent magnet flux linkage, and no-load back electromotive force, and finite element simulations were conducted on motor models with different layers. The calculation results show that the calculation accuracy of the equivalent magnetic circuit model in this paper is similar to that of the three-dimensional finite element method, and the time consumption is very short, which is more conducive to the initial engineering calculation of this kind of motor.