The vibration response of approximately 200 trains is measured when they go through the adjacent non-vibration and vibration reduction section in Nanchang No.1 metro line. The data are analyzed in terms of different vibration evaluation standards. The vibration of the tunnel wall is significantly reduced with a steel spring floating slab, but that of the plate itself increased greatly. The variety of train trips more substantial influence on the low-frequency section and the tunnel wall height measurement points than that on the z-direction vibration. The wall′s vibration is magnified during the low-frequency band. The source strength of Nanchang metro is measured 76.66dB at the low point on the tunnel wall according to its maximum z-direction vibration (VLzmax), which best fits the evaluation. Since assessment differs when the measurement height and standards are changed, VLzmax is recommended to evaluate the vibration reduction of the floating slab.