To investigate the structural vibration characteristics of parallel transfer subway stations under the mutual influence of trains on different lines, this study integrates vehicle-track coupling dynamics analysis, finite element simulation, and field tests at subway stations. It analyzes the transmission characteristics of vibrations within buildings and the impact of combined train operations on structures, offering vibration reduction suggestions. The results indicate that platform vertical vibrations predominantly occur within the 30~80 Hz frequency range, with distinct peaks at 36, 47, 67 Hz. Due to the superposition of incident and reflected waves at the top layer, vibrations are amplified there, with an average amplification of 4.50 dB, and the lateral transmission attenuation rate is approximately 0.51 dB/m. When trains operate simultaneously on both lines, the Z vibration level at central sampling points above the lines is higher. To comply with vibration limits, the entry speed should be restricted to no more than 22 km/h. The vibration reduction fastener achieves an effect of 3.80 dB. Except for its inherent frequency range of 11~14 Hz, the steel spring floating plate exhibits significant vibration reduction in other frequency bands, notably reaching 28.00 dB at the 80 Hz band.