The sources and supply passage of the water inflow in K27+227~+248 section of Zhongliangshan tunnel are analyzed on basis of hydrogeology analysis, transient electromagnetic detection and radar detection. Comprehensive treatment measures, including water releasing in deep layers, consolidation in shallow layers and deep watersealing curtains, are proposed. Proper grouting materials are selected according to the features of different grouting stages and good results are achieved. The rules and control factors of the deformation of the surrounding rock during grouting are determined by means of deformation monitoring and numerical simulation, so as to prevent the surrounding rock from being damaged by the increasing water pressure and grouting pressure. In the end, the stability of the surrounding rock during grouting is guaranteed and the water inflow is successfully sealed.