Abstract: The common analytical method for pipeline two-phase flow with column separation includes bubble flow model and concentrated cavitation model. The concentrated cavitation model is widely used because it is simple and easy to be combined with Method of Characteristics (MOC). Amelioration is made to the Streeter ~ Wylie's vapor-liquid model (model 1), resulting in a new concentrated cavitation model (model 2). Numerical simulations are conducted to compare the two models. Because the latter model (model 2) takes into account the variation of the length of liquid column and the height of the free surface due to the vapor volume, and the mass balance between the section in which vapor vacuum occurs and the upstream and downstream sections, the latter model (model 2) reflects the real status of two-phase flow in pipeline more effectively and is superior to the former one.