The anti-seepage curtain engineering for expansion of underground building of Wujiangdu generating set is situated at the place where Karst is well development, which reflects the complex engineering geology conditions. Furthermore, the geological structure mainly consists of deflected faultage within strata, accompanied with some matrue vertical obliquity faultages, intensively extruded rock strata, mature faultages, joints, and fragmentation, mature horizontal Karst and vertical Karst. This paper takes this engineering as an example to introduce the process of high-pressure-grouting, and elaborates some special problems in high-pressure-grouting and puts forward disposal methods.