Abstract: This paper introduces a kind of in-situ stress test method and principle which have advantages of simple in operation,wide application and comprehensive calculation results with high precision. Using JHDC-1 in-situ stress sleeve fracturing test instrument,and according to the elastic mechanics theory combining with actual geological condi- tions in coal mine,the maximum and minimum horizontal stress and tectonic stress of the test point can be determined only by one hole fracture,and the value and orientation of principal stress of the test point can also be calculated. This test method is simple,fast and very suitable for coal mine ground stress test.