To accurately and sensitively track the stator current of the induction motor (IM) and detect faults, stochastic resonance (SR) and Teager energy operator (TEO) are combined to detect the fault in the residual stator current of sliding mode observer (SMO) under strong noise interference and complex weak fault conditions. Firstly, a new approach law is constructed to establish an SMO for better state tracking. Secondly, SR is used to absorb noise and amplify the detection residual of the SMO, and the output results are estimated by TEO in the time domain to achieve fault detection. Finally, the detection results of IM stator and rotor winding faults and sensor intermittent faults are presented. The experimental results show that the SMO has higher state tracking accuracy and a faster rate of convergence. Moreover, the residual of stator current is processed by SR and TEO, and the effectiveness of fault detection is enhanced.