The squirrel cage induction motor is prone to rotor breakage, which endangers the safe operation of the motor. For the issue of rotor bar breakage faults in squirrel cage induction motors under different operating conditions, this study employs the finite element method (FEM) using a Y-112 M-4 type induction motor as an example. Finite element models of both healthy and faulty motors were established under no-load, half-load, and full-load conditions to perform transient magnetic field calculations. The analysis focused on changes in stator and rotor currents. Based on the calculated electromagnetic losses, the three-dimensional steady-state temperature field distribution of the motor was determined. The results revealed that the temperature distribution of the motor will increase in different degrees under different fault conditions. This paper aims to provide valuable references for identifying the root causes of faults and forecasting their development trends. This offers novel insights into the reverse engineering optimization and manufacturing process improvement for the critical weak points of the squirrel-cage rotor.