Abstract: In terms of heat load problems of Zaozhuang Oil Pump Station, site testing for flue gas of heat medium heater, specific heat capacity of heat transfer oil, fuel oil and thermal efficiency of heat medium heater were carried out. The thermal efficiency of heat medium heater was evaluated according to SY/T6275－2007 《Energy Saving Monitoring Criterion for Oil Production System》. The results indicated the actual heat-carrying capacity of heat transfer oil had a decrease of 22% to the designed capacity, which led to the increase of exhaust gas temperature and the decrease of thermal efficiency. Replacing heat transfer oil, clearing the soot of heating surface of heater tube, and enhancing the heat insulation of exterior surface of heater body were proposed to improve the thermal efficiency of topping heater.