<p>Vibration-damping tracks of an urban rail transit vibrate under train loads and are a source of acoustic sound radiation in urban rail transit. In addition, they exhibit their own vibration amplification phenomenon during service. To evaluate the acoustic properties of damping tracks, this study considered acoustic wave superposition (AWSM) and examined a steel-spring floating-slab track (SSFST). This study focused on floating-slab (FS) acoustic radiation prediction and proposed a fast prediction method for the acoustic radiation of a track structure with a more regular shape. The influence of the structural parameters of FS on its acoustic characteristics was analysed and suggestions regarding the application of acoustic vibration characteristics were provided. The steady-state frequency-domain acoustic radiation prediction method exhibited high solution efficiency compared with the acoustic boundary element method, and was combined with the vehicle-track coupled dynamics theory and AWSM. The proposed method can be used to predict the acoustic radiation characteristics of regular structures and quickly evaluate the acoustic radiation effects. In addition, the FS has a strong low-frequency acoustical sound radiation ability, rendering it an important low-frequency acoustical sound radiation source for urban rail transit. The length and thickness of the FS significantly affected its acoustic vibration characteristics; therefore, a longer FS can be considered for sections with higher requirements for low-frequency noise. In the standard range, selecting a thicker FS offers advantages in terms of the acoustic sound radiation and vibration characteristics.</p>