Abstract: Patrol inspection is one of the vital means of equipment management and failure diagnosis. Therefore, performance degradation assessment plays a great role in patrol inspection system. In this paper, an idea of separating the model training phase and diagnosis phase is presented based on the research of methodology of performance degradation assessment. The system structure and the design of software combined with hardware are introduced in detail. With this system, the portable vibration analyzer can assess the performance degradation directly as well as forecast guide alarm thresholds setting. Finally, a bearing accelerated life test is performed to validate the designed system. The results show that the system is both feasible and effective.