Abstract: For the complex geological conditions such as large buried depth and high ground stress，the existing supporting body can not adapt to the large deformation of the surrounding rock，resulting in the failure of the bolt and cable support to break.Based on the detailed analysis of the mechanism of the yield-damping mechanism of the bolt （cable） support body，the key technology for the yield-damping function of the bolt （cable） support body （yield point and yield distance and shock absorption capacity） is proposed，and the characteristics of single gun barrel and new pressure relief device commonly used in engineering are compared and analyzed.The study results show that:①under the same height of new pressure relief device，the pressure points corresponding to the wall thickness of 3.0 mm and 3.5 mm are 60 kN and 73 kN respectively，and the pressure of the confinement ring is larger，so the larger the wall thickness of the confinement ring，the larger the pressure point;②under the same thickness of the confinement ring，the pressure distance is about 15 mm at a height of 35 mm，and the pressure is about 20 mm at a height of 40 mm，with the increase of the height of the confinement ring，the pressure distance is also increased correspondingly;③when it is subjected to external impact load，its elastic compression capacity can reach 4~5 mm，the ability to absorb shock loads is obvious and the pressure damping effect is remarkable，the compression distance of the single gun barrel is only the 1/2 of the one of new pressure relief device，and the impact deformation at different impact heights is only about 0.5 mm when subjected to external impact loads.There is a significant lack of elastic recovery ability after compression，and the damping effect is not obvious.

Key words: Bolt （cable） support body, Yield-damping, Yield point, Yield distance