In order to solve the problem of determining the technical policy limitation of separate-layer water injection technology in extra-high water cut period of oilfields, many typical injection and production well pattern models was established, considering the effects of factors such as physical property, pressure, layer number and layer length on water intake capacity and fluid producing capability of each layer comprehensively. Differential of water-cut escalating rate was used as the equilibrium displacement criteria of reservoir in extra-high water cut period to accurately indicate the influence of main factors. The Lorenz coefficient was used to characterize the vertical equilibrium utilization level, and finally the technical policy limitation of separate-layer water injection technology in extra-high water cut period of different prosody features and different well pattern forms were obtained. The influence of various factors was analyzed and the main control factors affecting the technical policy limitation of separate-layer water injection technology in extra-high water cut period were obtained. The practical example shows that the technical policy limitation of separate-layer water injection technology in extra-high water cut period can provide convenience and guidance for field development.