In order to stabilize the achievements of poverty alleviation and realize rural revitalization, it is a key issue to effectively prevent and control the risk of returning to poverty after tourism in underdeveloped areas. Based on the vulnerability assessment theory and comprehensive risk management theory, this study took tourism poverty alleviation in underdeveloped areas as the research background to construct the theoretical framework and evaluation model for the risk of returning to poverty, and used the Tianzhu Mountain tourism area in the Dabie Mountains as an example to empirically analyze the risk of returning to poverty and its internal driving and prevention and control mechanisms. The results show that in underdeveloped tourism poverty alleviation areas, the stability of poverty alleviation is generally high. Compared with non-tourism participating farmers, tourism participating farmers have higher stability of getting rid of poverty and lower risk of returning to poverty. But with the participation in tourism from low to high, the risk of returning to poverty shows a U-shaped change, that is, farmers with high participation can be affected by the vulnerability of tourism, which leads to a reverse increase in the risk of returning to poverty. Besides, the influencing factors of the risk of returning to poverty include endogenous and sudden onset factors. For different types of poverty alleviation farmers with tourism participation, the effects of the two factors are also different. For tourism participating farmers, on the one hand, health impact and human capital play a key role in the risk of returning to poverty, and affect it through the diversity of farmers'livelihood and non-cognitive ability reflecting personality traits. On the other hand, the risk of returning to poverty has spatial heterogeneity. The higher the risk prevention and control ability and resource endowment of tourist destinations, the lower the risk of returning to poverty of farmers. Finally, underdeveloped tourism areas should build a multi-dimensional prevention and control mechanism for the risk of returning to poverty, which takes target management, organizational level and risk factors as the framework, goal setting, comprehensive management and control, normalized governance, system improvement, information communication and collaborative supervision as one. This study can provide beneficial policy enlightenment for the risk of returning to poverty prevention and control and rural revitalization in less developed regions of China.