The special subject"research on life prediction technology of important in-service pressure vessels" mainly analyzes the failure mechanism of large-sized important and critical in-service pressure vessels under the action of working medium and investigates safety assessment and life prediction technology with a view to enhance the operation reliability of in-service pressure vessels in China. Based on a series of accident investigation and test & measuring research, the cause of cracking of catalytic regenerator is analyzed and the in-line non-destructive examination method and failure prevention measures for the cracking of catalytic regenerator are proposed.