Sand mining can meet market demand and promote local economic development, but it has an impact on riverbank stability and embankment safety, and currently there is still a lack of quantitative research on the safe distance in this regard. Therefore, this study used a seepage finite element analysis method and the Swedish arc sliding method to establish a calculation model for embankment seepage safety and anti-sliding stability based on hydrological surveys and topographic and geological survey data and applied them to a case study of the embankment from Yingtian to Leishi in the tail of the Xiangjiang River in Hunan province, China. The results show that high-intensity sand mining activities can cause serious river channel incision, destroy the balance of river scouring and silting, and easily cause bank slope reconstruction and steep slope collapse; sufficient mining ban areas and safe distance need to be retained to ensure the safety and stability of the embankment. The research methods and conclusions can provide a reference for river sand mining planning, river dredging, and embankment design.