This paper conducts an in-depth study of the impact of passenger vehicle thermal energy storage systems on interior noise propagation and noise reduction, utilizing a comprehensive approach of theoretical analysis, model design, experimental simulation, and verification. By constructing a coupled model of the thermal energy storage system and interior noise propagation, simulations were performed using professional software such as ANSYS and COMSOL. Operating conditions included various speeds, including 30 km/h, 60 km/h, and 90 km/h, and ambient temperatures, including –10 °C, 25 °C, and 40 °C. Simulation results demonstrate that the thermal energy storage system significantly shifts the noise propagation path by altering the interior temperature distribution and air density. Within the specific frequency range of 200-800 Hz, the noise reduction is stable at 3-5 dB, with the most significant reduction reaching 4.8 dB around 500 Hz. The deviation between the experimental verification results and the simulation data was within 5%, demonstrating high consistency and an acceptable level of consistency.