Abstract: To study the mechanical properties and deformation characteristics of the ballast track on kilometer-span bridges of continuous welded rail (CWR) in high-speed railways, a spatial coupling model of the CWR-ballast track-kilometer span bridge was established based on the principle of the beam-rail interaction. The influence of temperature difference in structural components of the suspension bridge on the longitudinal force and deformation law of CWR was analyzed, and the vertical deformation characteristics of CWR were proposed. Furthermore, the regularity of CWR on the bridge was evaluated using the midpoint chord measurement, and the baseline length measurement. Results show that it is crucial to install rail expansion joints (REJ) at the main beam's end to ensure the strength and stability of the track on the bridge meeting the requirements of the specifications. The temperature differences between the main beam and the main cable of the suspension bridge component are the main factors affecting the longitudinal force of CWR, with the suspenders and the bridge towers having minimal impact. The primary factors affecting the alignment of the track on the suspension bridge are the temperature difference of the main cable, the bridge tower, the suspenders, and the main beam, with the sensitive areas of track deformation mainly concentrated in the mid-span area of the main bridge and the main tower area. Under temperature effects, the high and low unevenness on the suspension bridge is mainly concentrated in the bridge piers, bridge towers, and mid-span areas of the bridge. The research findings serve as valuable references for designing, operating, and maintaining CWR on kilometer-span suspension bridges.