Abstract: Traditional researches have focused on the definition, measurement, root causes and reduction strategies of poverty. With the application of concepts such as "ability" and "risk" in the field of poverty research, vulnerability has become a hotspot of poverty research because of its forward-looking perspective. In the face of unfavorable external shocks, poor people generally have high vulnerability. The vulnerability of poverty research can predict the future of poverty, improve the efficiency of poverty reduction and take into account the risk of future shocks and ability to cope with risk. The vulnerability research based on livelihood capital can effectively be used to identify vulnerable groups and guide the formulation and adjustment of rural poverty alleviation policies. Studies of vulnerability to poverty are mainly aimed at the meaning and the measurement of poverty. Domestic literatures combined with actual situation have mostly drawn lessons on foreign to empirical tests with relevant survey data. Taking Pingshang Village in Minxian County as the research area, this paper constructed an evaluation index of vulnerability of poor households from three aspects-risk, livelihood capital and adaptability. We used household index data to analyze the key factors that affect the vulnerability of poor farmers based on the comprehensive index method and according to the divisions of sustainable livelihood framework of livelihood capital. The aim of the study was to provide references for effectively distinguishing vulnerable groups of poor farmers, and establishing and adjusting the policy of rural poverty alleviation. The results showed that:1) social and human capitals of Pingshang Village farmers were high and natural and material capitals low. 2) The farmers' natural disaster and economic activity risk indexes were high. 3) Adaptability was generally low and many adaptive measures to deal with the risk had no practical effect. 4) The vulnerability of farmers was negatively correlated with income and education levels. The vulnerability of young and middle-aged households was lowest, and households headed by the elderly were the most vulnerable. Risk and adaptability were closely related with capital status of farmers. If capital was reasonable, impact of risk was generally small, adaptability strong and fragility low. Half of rural households in the study area suffered high-risk shocks, severe lack of livelihood capital, low adaptive capacity and high levels of vulnerability. Based on the conclusions and actual situations in the study area, suggestions were put forward to reduce vulnerability of poor farmers. This included developing characteristic industries, changing traditional modes, expanding labor markets, improving network systems and establishing mutual help platforms. In order to identify vulnerability of disadvantaged groups at micro-scale, poverty alleviation policies needed to strengthen identification of vulnerable groups. The establishment of poverty vulnerability assessment indicators still needed further inspection and adjustment. Risk management, poverty forecasting and anti-poverty were key research priorities.