China's role as a mediator between Saudi Arabia and Iran was surprising to many observers, because until recently, Beijing avoided from interference in prominent events on the world stage. China would prefer not to assume the responsibility of controlling threats to stability and give the UN an observer role in global events. Chinese mediation was new and clear evidence that Beijing has turned from Deng Xiaoping's principle of staying in the background diplomacy to the more active diplomacy of a great power. The aim of the current research is to investigate the role of China in mediating between Iran and Saudi Arabia based on Simon's decision-making theory related to risk management. Therefore, the basis of the questions of the current research is that why did Iran and Saudi Arabia choose China as a trusted and effective mediator? In response, this hypothesis is proposed that China's advantage for Iran and Saudi Arabia lies in its diplomatic paradigm, which includes avoiding taking one side and trying to bring both sides closer to each other, ability to take advantage of China's growing geo-economic influence and this country refrains from using force in regional affairs. The aim of this approach is to provide a new method for China's participation in regional peace affairs.The results of the research indicate that the success of China's mediation can be attributed to Beijing's diplomatic approach of non-commitment and non-intervention, which is based on China's neutral image between Iran and Saudi Arabia and its long-term accumulation of economic ties.