The accurate analytical inductance model is an eff ective tool for performance evaluation and preliminary design of singletooth winding segmental rotor switched reluctance motors (STSSRMs). Due to the discontinuous rotor structure and the special magnetic circuit, the analytical inductance calculation of the STSSRM is more complicated than that of the conventional SRM, and it is hard to obtain the accurate inductance at each position directly. To solve this issue, in this paper, an accurate and fast analytical approach is proposed to determine the phase inductance of STSSRM at any rotor position. Firstly, with the analysis of the fl ux line distribution, the fl ux tube models and the equivalent magnetic circuits at three critical positions are established to calculate the corresponding permeance and inductance parameters. Secondly, according to the proper approximation in a certain region, an additional critical inductance point is obtained to improve the accuracy of the inductance model by utilizing the quadratic interpolation calculation. Furthermore, with the four inductance values at diff erent rotor positions, a third-order Fourier series inductance model is developed for analytical inductance calculation, where high calculation accuracy can be achieved. The eff ectiveness of the proposed method is verifi ed by fi nite element simulation and experiment.