Combining Schwarz–Christoffel transformation, magnetic field reconstruction method, and Maxwell stress tensor method, the calculation model of cogging torque of a dual‐stator axial flux permanent magnet machine is established. The end effect and slotting effect are both been taken into account. The results are verified by finite element method. And with the proposed method, calculation time can be significantly reduced compared with finite element method. Three measures to reduce the cogging torque of dual‐stator axial flux permanent magnet machines are discussed based on which the cogging torque is optimized by genetic algorithm. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.