Abstract: There're many geological flaws developed in dam foundation of JinpingⅠHydropower Station, it's necessary to be disposed weak rock zone such as fault, crushed zone and rock vein by cement-chemical composite grouting method. The inspection result after grouting shows that the anti-permeability and deformation capability of the structural plane such as rock massive and rock chips types, rock chips with mud and lamprophyre vein obtained great improvement. The enhance range of the sound wave velocity, deformation modules and all kinds of characteristic index after grouting would be provided reference for the similar projects.