A preliminary simulation of gas-liquid two-phase flow in parallel flow field was studied in this paper.The VOF two-phase flow model was used to model the transient process of gas drains the liquid water from the channel with the initial liquid distribution at the bottom of the flow field.At the vertical orientation，the effect of gravity on the liquid transfer was analyzed.The result showed that the parallel flow field did not suit for liquid drainage and the liquid distribution was inhomogeneous.To improve the liquid drainage，the inlet manifold was changed with gradual decreases of vertical section.It’s found that the new style manifold can change the water distribution in the channel and improve liquid drainage performance of embranchment channels.