###### Abstract  
Forest ecological security is related to national ecological security. Yunnan Province has a significantly stereoscopic climate characterized by diverse and complex vegetation. Therefore, the ecological security of Yunnan Province's forests, which span multiple climate zones, must be carefully considered. The purpose of this study is to evaluate the forest ecological security situation and influencing factors in Yunnan Province in 2017. Utilizing data from remote sensing, the Yunnan Province Yearbooks, socioeconomic statistical data, and better pressure-state-response modeling, this work produced an index system containing state and societal pressure. The evaluation indicators were weighted using a combination of entropy weighting and expert weighting, using 16 prefectures in Yunnan Province as samples. Using the fuzzy matter-element technique, the forest ecological security situation in Yunnan Province in 2017 was assessed, and the contributing causes were examined. Results indicate that there are spatial distribution differences in ecological security in various regions of Yunnan Province. The regions with the greatest indices of forest ecological security were found in Xishuangbanna in the south and Nujiang and Diqing in the northwest of Yunnan Province, while those areas with the lowest indices were distributed in Qujing and Zhaotong in the northeast and Baoshan in the west. Results of the grey relation analysis show that those factors that influence forest ecological security across different prefectures showed significant diversity. In Yunnan Province, the main influencing factors include days when the air quality reaches Level 2 or higher, the percentage of natural forest acreage and accumulation, the value of forest ecological service function per unit area, the annual average temperature, and forest coverage. The influence of the forest status index was greater than that of the forest pressure index. The findings of this work can guide decisions related to regional forest ecological security construction across multiple climate zones. In view of the differences in ecological security status and influencing factors in different regions, ecological environment governance should be adapted to local conditions to ensure the coordinated development of nature, the economy, and the ecological environment. forest ecological security; system of evaluation index; spatial distribution; affecting factor; gray correlation; Yunnan province; multiple-climate zones 20232010  
ecological security issues have received significant research attention [7; 8; 9; 10]. The importance of ecological security has also increased in China, both on a regional and national scale [11; 12]. The natural ecosystem is dominated by forests that are related to national ecological security. Forests not only maintain the diversity of biological populations but also play an important role in maintaining ecological balance [13; 14]. However, with the continuous development of the social economy, humans have imposed unbearable pressure on forests [15]. Human occupation and the resulting deforestation reduce both the area and accumulation of forests [16], which subsequently result in soil loss [17], vegetation reduction [18], species endangerment, ecological imbalance [19], climate change, and increased greenhouse gas emissions, all of which threaten the sustainable development of humans. Aiming at finding ways to ensure the stability of forest ecosystems, a large number of researchers are committed to forest management [20], forest ecological functions [21], forest ecological services [22], forest health [23; 24; 25], and forest security [26]. While many studies have assessed ecological security across regions, they have only focused on a few forest types and climatic zones and rarely evaluated the ecological security of forests spanning different climatic zones. China has experienced rapid urbanization and socioeconomic development since its reform and opening up in 1978 [27].