A numerical simulation of laser cladding process on the surface of nickel-based superalloy GH4169 with coaxial powder feeding system is carried out by Marc software. The influence of different repair cross sections on the distribution of temperature and residual stress field is studied through a directly coupled thermo-mechanical analysis. The results show that for single-path laser surface reparation, different repair cross sections lead to different distribution characteristics of temperature and residual stress field in the bonding zone. The parallel component of residual stress is evidently larger than vertical component in the direction of the scanning path when it is repairing on a plane. The vertical component of residual stress is relatively increased due to the constraints from two sides of the crater when it is repairing a crater of a long strip with rectangular or arc-shaped cross section. As the aspect ratio of the section increases, the ratio of vertical component of residual stress to parallel component also increases. However, the ratio of vertical component of residual stress to parallel component for arc-shaped cross section is smaller for the same aspect ratio. In order to avoid the deformation of the thin-walled parts, an arc-shaped cross section with small aspect ratio is recommended.