Abstract: The Tahe oil field is a carbonate ultra-deep and ultra-heavy oil reservoir featured by production based on dilution, complex oil-casing annulus environment and deep wells. Test personnel and ground interference also led to a low success probability of liquid level measurement and affected management of mechanical pumping wells heavily. This paper analyzed the main factors which influenced liquid level test in the Tahe oil field in view of the characteristics of mechanical pumping well in heavy oil reservoir. A new dynamic liquid level calculation method using work diagram load was applied to solve the difficulty of distortion of liquid level. The method can be adopted to conduct the production management of mechanical pumping wells in heavy oil reservoirs.