The filtration and separation area of a station on the China?Russia East Route is set as parallel pipelines,and the uneven distribution of branch flow may occur due to the differences in internal pressure and pipeline layout,which affects the filtration efficiency and the overall work efficiency.In order to avoid pipeline bias, the flow direction of the filtration and separation area is studied based on computational fluid dynamics (CFD).Results show that pressure distribution, turbulent flow distribution, frictional resistance loss along the system,fluid inertia and other factors affect the branch pipe flow distribution.Among 11 parallel pipeline configurations,the axial inlet and radial outlet configuration (Type 3) with inlets and outlets on the same side exhibits the least flow maldistribution overall.Under normal working conditions,flow maldistribution decreases with increasing manifold diameter and branch pipe spacing within the calculation range.Fault conditions,such as branch pipe blockages,significantly exacerbate flow maldistribution in the system.It is concluded that the flow distribution rule and the main factors affecting the flow distribution are obtained,which is helpful to guide the design and construction of gas transmission station.