Abstract: In view of the poor effect of traditional profile control technology in high water cut stage,the profile control mechanism of different water cut stages was studied.By using numerical simulation,the waterflooding levels of reservoir in high water cut stage were classified,the corresponding technical countermeasures for different waterflooding levels were developed.The results indicate the profile control effect was the joint effect of swept volume expansion and pressure gradient fluctuation.In medium-high water cut stage,it was effective with long duration,while in extra high water cut stage,it was effective with long duration,which was mainly caused by the role of pressure gradient fluctuation.High strength plugging agent governance extra high water flooding area was the foundation to improve the oil recovery,high strength mobility regulatory governance high water flooding area was the key,and relative permeability modifier governance medium water flooding area was the core.