The utility model provides a bolt pretightning force is controlled packing ring and is used its bolt pretightning force controlling means, relates to test device's among the aircraft structural test structural design technical field for judge whether the bolt pretightning force reaches the greatest stress that the structure can bear, utilize the pretightning force will split the key and press absolutely, reach the purpose of controlling the pretightning force. The pretightning force that produces when tighten nut pushes down the packing ring body, because the fracture key produces the extrusion with the top ring, produces ascending zhi fanli, and this zhifanli when reaching the setting value breaks the fracture belt. Adopt the utility model provides a bolt greatest stress that bolt pretightning force is controlled packing ring and is used its bolt pretightning force controlling means control structure piece can bear, but direct control pretightning force, it is uncontrollable to have avoided screwing up the moment pretightning force that uncontrollable factors caused in to pretightning force conversion process.