Abstract: The vibration energy of automotive exhaust systems is transmitted to the chassis and body structure through hangers and suspension components, directly affecting the vehicle's Noise, Vibration, and Harshness （NVH） performance. This study employs the finite element method to analyze the dynamic characteristics of the exhaust system, focusing on numerical evaluations of first-order modal parameters （constrained and free modal） and dynamic stiffness properties of hangers. According to industrial standards, the performance validation of a specific vehicle's exhaust system reveals that Hanger 4 exhibits a marginal compliance with the preset frequency threshold （302.7 Hz vs. required ≥300 Hz）. Structural optimization is implemented for Hanger 4 by increasing the wall thickness of the connected exhaust pipe from 1.2 mm to 1.5 mm, followed by static analysis to assess the mechanical performance of the optimized model. Post-optimization results demonstrate a significant improvement in Hanger 4's first-order free modal frequency （354 Hz） and dynamic stiffness curves fully below the target threshold （500 N/mm）. Furthermore, critical parameters under 1G static load—support reaction force （46.895 N） and displacement （3.895 mm）—and weld stress （40.903 MPa） under 4G static strength conditions all meet design specifications. This research validates the targeted enhancement of NVH performance through structural optimization, providing an effective solution for addressing hanger failure in engineering applications.