Abstract: Modern society is a risk society. As China's social and economic development, a large number of rural left-behind children appeared in the transfer process of a lot rural labor force. They encounter a variety of risks, and their security situation is worrying. This research embarks from the perspective of risk society theory, explores the social risk problems of rural left-behind children, including accident risk, loss risk and health risks; on this basis, this paper discusses the system, culture, individual factors of social risk of the rural left-behind children, from three aspects of breaking urban and rural dual system, increasing investment, strengthening rural education and establishing and improving the social support system to deal with these problems.