With the rapid development of petrochemical enterprises in China, the competition among enterprises has become increasingly fierce, and energy saving, consumption reduction, cost reduction and efficiency improvement has become an inevitable trend of sustainable development for chemical plants. From the aspects of optimized COT control of cracking furnace, optimization of coke burning scheme, chemical cleaning of convection section, hydraulic coke cleaning of quench boiler and hole enlargement of dilution steam control valve of gas-phase furnace, the cracking furnace management was optimized to improve the operation efficiency of cracking furnace and reduce the energy consumption of ethylene plant.