Abstract: The vulnerability of agricultural drought disaster reflects adaptability, reaction ability and coping ability of agricultural system for drought, and its research has positive effect for disaster prevention under certain strength of disaster-causing. The paper presented threshold value of grade interval of estimation for vulnerability of agricultural drought in Hengyang city. According to variable fuzzy set theory, the variable fuzzy analysis method of multiple attribute and grades was proposed for quantitative estimation for vulnerability of agricultural drought disaster. The results of quantitative estimation showed that the grade of vulnerability of agricultural drought disaster was at grade three in Hengyang city, the order of strength was Hengnan, Hengyang, Changning, Hengdong, Hengshan, Leiyang, Qidong, which objectively reflected the actual situation of vulnerability grade of agricultural drought disaster.