Abstract: Mixing light-oil production to the heavy oil of carbonate reservoir was performed in Tahe oilfield. When the electric pumping well stops diluting oil the measurement of dynamic liquid level may faces the risk of electric current elevating, overload and lie down, which increases the production cost. Meanwhile, the existence of foam section and negative pressure in the space tube and casing in the diluting oil process has resulted in lack of dynamic liquid level data for the pumping wells and has limited the development of the oilfield. Pressure-out method was used to calculate the dynamic liquid level for electric submersible pumping well, which was based on the relationship among the frequency of electric pumping wells, head relations and total pressure head. Finally, the calculating formula of dynamic liquid level was first deduced, and then was applied to abundance field comparison experiments. Results from the field proved to be reasonable and reliable, which can be used to direct production.