The performance of high-speed motor control systems relies heavily on rotor position detection, with the use of a resolver allowing for the acquisition of high-precision absolute position signals. This paper provides a detailed examination of the structure and working principles of the resolver, as well as the factors that influence its output signals. Using Python software, we simulated the controller’s angle decoding of the resolver’s output signal, obtaining the harmonic content and angle deviation of the resolver’s signal. Furthermore, through analysis, the study elucidates the mechanism by which the coupled magnetic field in electric drive environments affects the resolver’s output signal. During engineering development, it was observed that housing the resolver and motor in the same enclosure causes interference. The motor’s spatial magnetic field disrupts the resolver signal, leading to signal distortion. This interference reduces the decoding accuracy of the resolver signal. In severe cases, this distortion can trigger hardware overcurrent and cause motor instability. The introduction of a shielding cover or modulation of the resolver filtering circuit within the controller can effectively reduce the extent of signal distortion. Notably, the addition of a shielding cover, which isolates the resolver from the motor’s spatial magnetic field, demonstrates a more pronounced effect in mitigating waveform distortion. This paper analyzes the causes of waveform distortion in this high-precision angular position sensor and presents effective suppression methods.