Taking Guangzhou as the research object, using the triangle model to establish the evaluation index system, the weight of each index is calculated by entropy weight method. The comprehensive index of water resources health and safety, water resources development and water resources security are calculated, respectively. The influence degree of each index is then calculated. We evaluated the water resources safety of Guangzhou from 2010 to 2016 from the time series and analyzed the main influencing factors. The results showed that the comprehensive index of water resources security in Guangzhou is a trend of strong safety to safety. The restrictive factors that affect the water resources security in Guangzhou are mainly the residents' disposable income, the total output value of the three gross output and the urbanization rate. To sum up, the current situation of water resources security in Guangzhou is relative safety. This research will provide a scientific basis for improving urban water resources security.