Abstract: Relying on the capacity expansion and revamp of 400×10³ t/a CCR unit built in the 1990's, a series of energy saving measures were taken considering the scale, process and energy utilization, which include:optimizing the feed scheme according to the characteristics of the feed to reduce the scale of reaction; utilizing the high-efficient welded plate heat exchanger and double shell side heat exchanger to enhance heat transfer; decreasing the outlet temperature of flue gas to increase thermal efficiency of heating furnace; and optimizing the heat exchanger process flow to lower the inlet temperature of air cooler, and maximizing to utilize the latent heat of evaporation in the top of the tower. As a result, the processing ability increased by 13%, while the comprehensive energy consumption decreased by 502.4 MJ/t.