The stator winding interturn short circuit fault can cause the air gap magnetic field distortion of doublyfed induction generators, which leads to the change of electromagnetic torque. The electromagnetic torque the same as electrical parameters can be used as the fault characteristics. The electromagnetic torque change characteristics before and after stator winding interturn short circuit fault were analyzed based on the energy method, and the multiloop mathematical model of doublyfed induction generators was established to calculate the electromagnetic torque of the normal and different degree of interturn short circuit fault. The harmonic variation characteristics of electromagnetic torque before and after the stator winding interturn short circuit fault were obtained by the spectrum analysis of the simulation results, which verified the correctness of the theoretical analysis. The correlation characteristics between stator winding interturn short circuit fault and electromagnetic torque could be used as the basis for fault diagnosis of doubly fed induction generators.