Abstract: After the heavy oil catalytic cracking unit in Refinery of Daqing Petrochemical Company was reconstructed in 2000, consumption of catalytic agents became larger due to the formal change of regenerator and irrational operation parameters. Analysis shows that this problem is caused by low regeneration pressure, resulted from equipment defects of the main air blower system and the irrational operation parameters. The regeneration pressure is increased by replacing the main air blower and adjusting operation parameters. The consumption of catalytic a-gents lower from 1. 2 kg/t to 0. 7-0. 8 kg/t, the operation cost and energy consumption are lowered, and the e-conomic benefits are improved.