[Objective] To effectively mitigate the vibration and noise of interior permanent magnet synchronous motor (IPMSM) and enhance its operational stability and reliability, this study explores the method of optimizing IPMSM vibration and noise by altering the air gap length. [Methods] An 8-pole 48-slot IPMSM applied in a wire drawing machine was selected as the research subject. The radial and tangential electromagnetic forces during motor operation were calculated and analyzed using the finite element method, and the force waves were subjected to two-dimensional Fourier decomposition to thoroughly investigate the order and frequency of the primary force waves. Based on this, modal analysis and vibration noise simulation analysis of the motor were conducted using Workbench, with a focus on comparing the vibration acceleration and a-weighted sound pressure level contour maps under different air gap lengths, revealed the variation patterns of vibration and noise characteristics. Taking into account the influence of the static eccentricity of the rotor on the radial electromagnetic force waves, the order changes of the radial electromagnetic force under the condition of a 2 mm eccentricity of the rotor were analyzed. [Results] The simulation results indicated that appropriately increasing the air gap length could reduce the motor’s vibration and noise levels as well as the amplitude of cogging torque to a certain extent. At the same time, the increase in air gap inevitably weakened the main magnetic field strength, led to a decrease in the motor’s output torque as the air gap increases. When the rotor was in a state of static eccentricity, it had an impact on the spatial order of the electromagnetic force, but it did not change the temporal order of the electromagnetic force. [Conclusion] In practical design, a comprehensive trade-off between noise reduction and torque performance is required. Additionally, rotor eccentricity significantly impacts the electromagnetic vibration and noise of the motor, so it must be avoided during both manufacturing and operation.