The excavation project for the pump room of a thermo-electric plant is close to hills. Its geological and environmental condition is complicated,which is disadvantageous to its design. According to the safe principle and convenient construction,punching cast-in-place concrete pile and steel box girder were adopted to support the structure. And the high pressure jet grouting was used to act as waterproof heavy curtain. Through the whole construction and monitoring result,it is shown that the design is reasonable.