The main function of the key ecological functional area is to provide stable and sustainable ecological services. Farmers, as the basic unit to maintain the function and the main economic activity subject in the area, face multiple pressures such as natural pressure, social pressure and political pressure. The interaction of pressure not only enhances the vulnerability of farmers’ livelihood, but also affects the main function of the area. Therefore, identifying the impact of multiple pressures on farmers’ livelihood will help to formulate effective mitigation measures for livelihood vulnerability. This paper takes the Yellow River Water Supply Area of Gannan as an example. Based on 549 household survey data and ordered logistic regression methods, we explored the key pressures of farmers and discussed the influence of living pressures’ interaction on livelihood capital availability. The results showed that: (1) Most farmers in the study area are under natural and economic pressures. The key protective region and restoration region are under the pressure of nature and economy, and the economic demonstration region is under the pressure of economy and society. (2) Under the multiple pressures, the social capital availability of farmers in the key protective region and restoration region is in a stable state, and the availability of other capital is decreasing. However, the financial capital availability and social capital availability of farmers in economic demonstration region are in a stable state, and the availability of other capital is decreasing. (3)The interactions of high marriage expenses and low prices of agricultural products, livestock diseases and shortage of drinking water, high tuition expenses for children and high marriage expenses as well as low prices of agriculture products and pension insecurity, high expenses for building houses and the ecological policy, and low employment rate for adult children and agricultural pests have the greatest impact on the availabilities of natural capital, physical capital, financial capital, social capital, and human capital, respectively.