To evaluate the energy-saving potential under different control precisions of molten steel temperature and operation time in BOF-CC section, a precise control model based on production practices is established. And a calculation method of planning extra temperature loss and production process temperature loss of the precise control model is proposed. Taking a steel plant production data of SPHC-W as an example, the energy-saving potential under existing control of molten steel temperature and operation time is calculated. The planning extra potential temperature loss is 7.25 ℃ and the production process potential temperature loss eigenvalue is 10.10 ℃. For further analysis under existing control the level, when the control accuracy of molten steel temperature is increased by 1 ℃, the production process potential temperature loss eigenvalue can be reduced by 0.33 ℃. When the control accuracy of operation time is increased by 1 min, the planning extra potential temperature loss can be reduced by 1.76 ℃ and the production process potential temperature loss eigenvalue can be reduced by 1.62 ℃.