The routine method using statistical analysis theory with enough historical data to predict risk factor probability (index failure probability) has defects, as historical data, especially the ones that far away from today, often can not precisely reflect the current situation of the gas network. Therefore, the risk factor probability should be predicted or evaluated by rational using the historical data and combining with the current situation. This paper presented a risk factor probability comprehensive evaluation model which considers historical data as well as the experts' analysis of the object system in recent years, namely, the risk factor probability evaluation model based on information revision, and employed for risk evaluation of the city gas transmission and distribution system with a case study. (C) 2016 Elsevier Ltd. All rights reserved.