Usually the water head of the pumped storage hydro-plant is high, generally up to 400-500 m, therefore the rock mass under the high-pressure bifurcation pipe have to bear as high as millions Pascal water pressure, in according with the requirements of high water head pumped storage hydro-plant should be 1.2 times of the water head special high-pressure packer permeability test compared with normal to test the permeability of rock and rock cleavage pressure value. The test results on the choice of design options often play a decisive role. Based on the engineering practice, the authors studied the drillhole high-pressure packer permeability test in the pumped storage hydro-plant’s underground powerhouse, by the analysis of test results, this article offers a demonstration of the deformation of rock fracture witch under building in the condition of high-pressure water head, it provides a more detailed engineering geological background. Usually the water head of the pumped storage hydro-plant is high, generally up to 400-500 m, therefore the rock mass under the high-pressure bifurcation pipe have to bear as high as millions Pascal water pressure, in accordance with the requirements of high water head pumped storage hydro-plant should be 1.2 times of the water head special high-pressure packer permeability test compared with normal to test the permeability of rock and rock cleavage pressure value. The test results on the choice of design options options often play a Based on the engineering practice, the authors studied the drillhole high-pressure packer permeability test in the pumped storage hydro-plant’s underground powerhouse, by the analysis of test results, this article offers a demonstration of the deformation of rock fracture witch under building in the condition of high-pressure water head, it provides a more detailed engineering geological background.