Because of the uneven transverse settlement of bridge piers caused by the parallel construction of existing and new high-speed railway lines, a CRTS III slab track-bridge system static-coupled model was established using the ABAQUS finite element analysis method for a commonly used 32m standard double-track multi-span simply supported beam bridge in high-speed railways. Considering different settlement types and settlement amplitudes, this paper studies the force between layers of track structure and the deformation law of rail surface caused by the uneven settlement of piers in the transverse direction. On this basis, the static damage classification and maintenance suggestions for the uneven settlement of single and double piers in the transverse direction under this type of bridge are proposed. Based on this analysis, static damage classification and repair recommendations were proposed for single and double-pier uneven transverse settlement of this bridge type. The results have shown that uneven settlement of the pier in a transverse direction has the greatest influence on the vertical irregularity of the rail surface, followed by the distortion and the horizontal irregularity, and the deformation extremum is easy to appear at the top of the settlement pier. When the unilateral settlement of the pier in the transverse direction of the bridge, the settlement difference between the singer pier of 10mm, 15mm, and 20mm, its damage classification is rated as II, III, and IV. It is necessary to pay attention to the bilateral settlement of the pier across the bridge, and the damage is more serious than the unilateral settlement. When the settlement difference of the transverse direction reaches 20mm, the transverse tensile stress of the self-compacting concrete layer exceeds the tensile strength limit of C40 concrete, and the track structure has the risk of cracking. It is recommended that the uneven settlement in the transverse direction of the single and double piers should be limited to 10mm or less for daily maintenance and that adverse settlement of 15mm or more should be avoided.