Abstract: To study the interior structural sound characteristics of APM (automated people mover) system, by establishing finite element simulation model, based on field tests and multi-system dynamics model, vibration excitations of off-vehicle motor and air spring are obtained. By applying excitations to car body and carrying out structure noise simulation tests, the interior structure noise sound pressure level and noise spectral characteristics are calculated and analyzed. Research results show that under the structural vibration excitation of motor and air spring, there are multiple peaks in the interior structure noise response, especially at 315 Hz, the A-weighted sound pressure level of each observation point is relatively larger. The carbody middle section generates larger structure sound, and compared with the other four observation points, the A-weighted total sound pressure level is about 3 dB (A) higher.