Abstract: ［Objective］ Construction deviation can affect project outcomes to varying degrees, making it necessary to study the impact of such deviations on the structural dimensions and vibration reduction performance of steel spring floating slabs. ［Method］ Focusing on the on-site construction deviation issues during the cast-in-place steel spring floating slab installation in curved sections of metro tunnels, a multi-process mapping theoretical model is established using mathematical geometry methods. By considering deviation combinations of different working conditions, the deviation ranges for the base and floating slab thicknesses are analyzed. Within these ranges, a dynamics model is built using ABAQUS software to evaluate the impact of construction deviations on vibration reduction performance. ［Result & Conclusion］ When the tunnel centerline deviates, the base thickness ranges from 75.72 to 281.75 mm, and the floating slab thickness ranges from 278.28 mm to 325.00 mm. Within the base thickness deviation, the peak of the rail vibration response is concentrated in the low-frequency range below 12.50 Hz. The greatest impact on vibration reduction performance occurs when the base thickness is 65 mm, reducing the vibration reduction performance by 23.90%. Within the floating slab thickness deviation range, the peak of rail vibration response is concentrated in the low-frequency range below 3.15 Hz. The greatest impact on vibration reduction performance occurs when the floating slab thickness decreases to 45 mm, reducing the vibration reduction performance by 24.24%.