Abstract: The study of flow characteristics in deformable pipelines is conducive to optimizing the design of pipeline shapes, contributing to engineering objectives such as improving transportation efficiency, saving energy, and so on. To address two-dimensional problems, the vorticity-stream function form equations were solved to simulate flow within deformed pipelines. Typical flow phenomena were analyzed by plotting vorticity contour lines and velocity profiles. The results revealed that concave deformations at the pipeline boundaries generated vortices at the rear of the concave deformation. When the amplitude of the concave deformation was significant, the generated vortices adhered to the upper wall, and the vortex region significantly expanded during the recovery phase of the deformation. Furthermore, an increase in the frequency of deformation led to the spatial proximity and subsequent coalescence of successively generated vortices.