In order to understand the ecological security situation of Dianjiang County, an ecological security evaluation and early warning model was established. The ecological security early-warning index system was constructed based on the stress, state and response framework model. And the subjective and objective comprehensive weighting method was used to determine the index weight. Then the regional ecological security early-warning model was established based on the extension cloud model for evaluating the ecological security of Dianjiang County from 2005 to 2015 and predicting the warning of ecological security in 2020. The results show that: (1)The overall ecological security level of Dianjiang County is relatively high in 2005-2015, and it is in the blue warning state in 2008-2010 and 2012-2015, but the development trend is declining. (2)Among the ecological security indicators in Dianjiang County, the per capita GDP, the green coverage rate of the built-up area, the intensity of environmental protection investment, and the number of hospital beds per 10,000 people have the most dramatic changes. (3)The prediction of ecological security level is yellow warning state in Dianjiang County in 2020; the population and the intensity of environmental protection investment would become the main factors affecting the ecological security of Dianjiang County. It is concluded that ecological security assessment and early warning can provide decision-making reference for the ecological engineering construction in Dianjiang County, which is of great significance to the maintenance of ecological security in Dianjiang County.