Sudden water pollution incident has the characteristics of instantaneity and uncertainty. Based on the characteristics, fuzzy fault tree analysis method was used to identify the potential risks of water pollution in Beibu-Gulf economic zone, and it also combined with the collected data and analysis results. The research results showed that the abnormal discharge of sewage was the main risk factor of the economic zone; the probability value of water pollution potential risk in this study area ranged from 4.6 percent to17.7 percent,which considered the random uncertainty and fuzzy uncertainty of the causes. This research could be considered as an instruction for future risk management, and it will play a great role in the healthy development of ecological environment.