For the oil fields developed by the production sharing model, the existing economic limit production calculation method is not applicable. In order to solve this problem, a calculation model of the production of the economic boundary of a single well with consideration of proportion is established by using the principle of break⁃even analysis and the reservoir engineering method. The new model is used to analyze the effects of the factors such as proportion, water⁃cut and oil price on the economic limit production. Under the same water⁃cut condition, the higher the proportion, the lower the limit production. The higher the water⁃cut, the higher the economic limit production. The limit water⁃cut chart of oil field is established. The higher the proportion, the higher the oil price and the higher the limit water⁃cut. Based on the technical and economic parameters of A oilfield, the economic limit production and water⁃cut under different conditions are calculated at oil price of 70$/bbl,and corresponding adjustment measures are proposed , which guides the treatment of low⁃production wells and reduces the operating cost. That shows the model can be used to sharing development oil field to determine the economic limit production and limit water⁃cut.