The reliability of processing center was evaluated and analyzed comprehensively.The failure data of each subsystem were collected to calculate the point estimate of mean time between failure（MTBF）,mean time to first failure (MTTFF),equivalent failure rate D and easy maintenance index K.The improved priority evaluation-AHP method was used to determine processing center reliability,the comprehensive weight and influence factor between each sub-system and reliability index.It effectively overcomes the defects of AHP,such as high subjectivity and low precision.The reliability comprehensive evaluation method was applied to evaluate the reliability level of processing center.The reliability index of processing center was obtained.