Building upon previously developed thin-film modular soft actuators for elongation and deflection, this study develops a modular soft robot for pipeline locomotion, addressing insufficient anchoring capability in confined environments. Conventional inflatable airbags typically expand into spindle-shaped geometries, resulting in limited contact length and reduced effective gripping stability. To overcome this issue, a corrugated thin-film gripping actuator is proposed, in which two high-aspect-ratio sub-airbags are arranged above a compression structure to regulate deformation through geometric constraints. Numerical simulation and experimental evaluation were conducted to investigate contact behavior and locomotion performance. Under an input pressure of 30 kPa, the proposed design achieves a contact length of 46 mm, compared to 37 mm for a conventional three-layer airbag configuration under the same conditions, corresponding to a 24.33% increase in a 10 mm plate-spacing environment. The gripping module is integrated into the modular framework to extend the motion primitives of the soft robot to include anchoring functionality. The results indicate that the corrugated structure effectively suppresses the spindle effect and improves contact effectiveness under compression. These findings demonstrate that structural regulation of thin-film pneumatic actuators provides a feasible strategy for enhancing anchoring performance and locomotion capability of soft robots in confined pipeline environments.