As a crucial industrial AC equipment, the motor is subject to rigorous safety and stability standards. However, due to the motor’s closed operation, it is challenging to detect and diagnose internal faults directly. This is typically achieved by monitoring the motor’s input and output current signals and developing algorithms to process these signals. This indirect approach allows for the identification of potential internal motor issues. In this paper, we present a series of simulation experiments designed to simulate the normal and faulty operation states of a three-phase asynchronous motor. The experiments employ the collection of three-phase current waveforms under different operational conditions, frequency domain analysis via Fourier transform, and the extraction and analysis of current harmonic components. The selection of the second and third harmonic components for the main characteristics of the current harmonic components serves as the basis for the judgment of detecting motor faults. This provides a theoretical basis for the actual harmonics detection and judgment of the fault design. This provides a theoretical basis.