Grottoes in China face a wide range of diseases, with water-induced deterioration being a key issue in their conservation. In order to better carry out the grotto protection work, the water-related problems in the grottoes have been sorted out in detail. This study identifies the primary water sources in grottoes, including rainfall, groundwater and condensate, and explores the water-induced diseases such as cracking, water erosion, weathering, biological damage, and material degradation and structural destabilization of grotto rocks caused by water as an intermediate or final medium. Finally, preventive measures against rainwater, groundwater and condensate are outlined to improve conservation efforts and provide theoretical references for grotto protection.