Research conclusions:In the works of the deep bore hydro － geological survey and the ground stress testing for railway tunnel，there are following three sectors to determine the whether the tests accuracy can be enhanced and whether the tests succeed or not: (1) Selection of the testing section: Dividing the test section that meets the test requirement is the prerequisite for the successful test．(2) Determination of water stop position on the top and bottom ends: The effect of the water stop is crucial to the success of the test．(3) Determination of the thickness of the test section: Determination of the calculation thickness of the hydro － geologic test plays a decisive role in accuracy of the test data．