Abstract: In the process of underground excavation,the surrounding rock in the high stress area is prone to dynamic damage,which poses a major threat to the underground construction personnel and construction equipment. In this pa- per,the rock testing system of true triaxial unloading disturbance is used to test the single-sided unloading disturbance of sandstone. The progressive failure law of surrounding rock in the single-sided unloading roadway of high stress rock mass excavation is studied. The mechanics and failure characteristics of single-sided unloading of high stress rock mass under the conditions of different initial stresses,different disturbance amplitudes and different disturbance frequencies are analyzed. The results show that ① when the single side is unloaded instantaneously,the axial strain has the phe- nomenon of instantaneous rebound compression rheology. The greater the axial stress,the smaller the rebound and the larger the compression. ② With the growth of the second principal stress,the failure strength first increases and then decreases,and the turning point of the failure strength is at the second principal stress of 20 MPa. ③ The single side unloading failure of high stress rock mass is a composite failure of tension splitting shear failure and the second princi- pal stress is the key factor to the final shape of unloading failure. When the second principal stress is 10 MPa,the ten- sile splitting shear crack appears in the sample. With the increase of the second principal stress,the shear phenomenon disappears and the cleavage crack increases. The cleavage failure of the specimen is almost complete when the second principal stress is 20 MPa. ④ Under the combined action of dynamic and static loads,the size of static load and the strength of rock sample are the main factors to determine the failure. Under the same disturbance condition,the static load is 80% of the failure strength,the failure strength is 148. 6 MPa,and the static load is 90% of the failure value, the overall failure strength of the rock sample is 142. 4 MPa. The larger the static load is,the smaller the trigger energy required for rock failure is. When the static load is the same,the lower the failure strength of rock mass is with the in- crease of disturbance amplitude and frequency. These have played an important role in the theory of surrounding rock support for excavation and unloading of high stress rock mass.