Engineering geological features for Powerhouse foundation of Guangzhao Hydropower Station is weak, which can not satisfy for the requirement of foundation design and deformation. Reinforcement treatment is performed. Wave velocity and deformation modulus of Powerhouse foundation rock is tested, and the relationship between them is established. The consolidate grouting and supplementary grouting is done with workplace weak rock foundation. The evaluation on grouting effect is by using the relationship of wave velocity and deformation modulus. The results show that there is a good effect on the P1 fracture zone, No. 5 karst conduit and T₁Yn⁴ clayed dolomite after the grouting treatment, especially for the rock mass which has a weaker characteristic under the natural condition. But for the rock mass which has good mechanics strength, the improvement effect is not very good. The deformation modulus has reached all design requirements.