The influence of polymer injection in the adjacent old test area leads to the uncertainty of injection-production capacity of Putaohua oil layer named PI1-2 in the up-exploit test area. In order to further study the change of reservoir percolation ability after the influence of polymer extrapolation in the old test area. In this paper, reasonable use of drilling shut-in time, four production wells in test area are selected to continuously monitor the producing fluid level height of production well, the data are analyzed and fitted, and the formation pressure is calculated by the method of static liquid level height of production well, and then the formation pressure can be grasped in time. The dynamic fluid level recovery method is used to calculate the formation pressure at different time, draw the fitting curve, and use Horner method to obtain the current formation permeability. Compared with the original permeability, the decrease of permeability in the area seriously polluted by polymers is larger than that in the slightly polluted area. The field application shows that the static pressure calculated by static liquid level method is compared with the actual measured pressure, and the error is within 8%.This method can be applied in the area where the measurement of static pressure is limited, and can be used to analyze the decreasing range of reservoir permeability after polymer contamination. Therefore, the decreasing range of reservoir permeability after polymer contamination is analyzed, which provides a basis for dynamic analysis and program making after polymer injection.