Based on the on-site conditions of the north and south anchor pit engineering of Liangqing Bridge in Nanning City, and taking into account the problems encountered in the construction of water-stop curtain using traditional sleeve valve pipe grouting method in karst areas, a simplified double sleeve valve pipe grouting method is proposed in this study. The construction process, operational key points, and effectiveness of the simplified double sleeve valve pipe grouting method are investigated. This method is suitable for deep foundation pit excavation in proximity to rivers and karst areas. It effectively improves the efficiency of hole grouting, solves the problem of excessive grouting volume and difficulty in filling the cracks due to rapid loss of grout through the fissures in the karst areas, and achieves the desired water-sealing effect. It provides valuable insights for water-stop measures in deep foundation pits in karst areas and holds significant potential for wider application.