According to the data from the investigation in some rural areas in Huaian, with SPSS and Stata data analysis software for data processing, we analyze the risk and related factors of catastrophic health expenditure of families with diabetic patients in rural areas, and calculate the inequality of catastrophic health expenditure by using concentration index. Families with diabetes in rural areas of Jiangsu Province have a relatively higher risk of catastrophic health expenditure which is more inclined to the low-income families. The lower the income of diabetic families in rural areas of Jiangsu Province, the higher the incidence and intensity of catastrophic health expenditure, which indicates that catastrophic health expenditures is unequal and easy to happen to the poor. Therefore, the government should improve the medical insurance system in rural areas to provide certain economic risk protection for diabetic families in rural areas, and reduce the economic burden of disease.