Due to the simplicity of integral path of Maxwell stress method, the accuracy of the air gap flux density directly affected the accuracy of the radial force. The calculation of air gap flux density in existing research based on Maxwell stress method was too simplified. Equivalent magnetic circuit method and Maxwell stress method were combined to derive the expression of radial force of stator when one phase was excited. In the angle position control (APC) mode, the analytical expression of the stator radial electromagnetic force during operation was derived. Comparative analysis of radial forces in the time and frequency domains by this method and the finite element analysis was performed. Results obtained by this method were in good agreement with those obtained by the finite element analysis with an error less than 10% at twice the rated current.