Quench oil circulating pump is the key equipment to ensure the safe and stable operation of ethylene plant. To solve the rolling bearing failure problem of quench oil circulating pump in the ethylene plant of SINOPEC Beijing Yanshan Petrochemical Company, the causes of the failure are systematically analyzed and demonstrated from the aspects of bearing design, installation and maintenance, environmental impact and maintenance management. It is found that the direct cause is the fatigue damage of rolling bearing and the root cause is the inadequate implementation of management measures.