Liquid production increase is an effective measure to reduce the decline of production in offshore oilfield at high water cut. Compared with traditional method，the dynamic analysis method based on dynamic production data of oil wells can evaluate liquid production increase potential and overcome the limitations and dependence on regional static data. But the conventional dynamic method can only calculate the dimensionless liquid production index and is hard to quantify the potential of liquid production increase. Dimensionless maximum reasonable production pressure difference of oil wells was calculated based on the direct quantitative relation between the dimensionless liquid production index and water cut which is established based on percolation theory. On this basis，the maximum daily liquid production of oil wells can be real-time calculated，achieving the purpose of quantifying oil well liquid production increase potential directly by the dynamic method. Application results show that the daily liquid production of each well has reached the design value after implementation in W oilfield，which proves the rationality of the method. Since only the data of daily liquid production and daily oil production of the wells are required，the proposed method overcomes the shortage of static data in offshore oilfield. This method has the features of accessible data，reliable calculation results and convenient implementation，showing a broad application prospect in offshore oilfield at medium-high water cut stage.