The stable control of the undercutting roadway during the service period is an important part of the production management of natural caving metal mines.When the undercutting roadway is arranged in the fault fracture zone,the complex structural conditions will intensify the damage of mining stress to the surrounding rock of the roadway.To clarify the essential reason for the failure of the surrounding rock of the undercutting roadway under the condition of high stress and complex structure,this paper constructs the fault activated slip mechanics criterion under mining disturbances and simulates the stress transfer of the weak layer surrounding rock of the undercutting roadway under different mining operating conditions.It is found that the failure caused by the bottom roadway under complex structural conditions can be summarized as a composite failure mechanism of fault activation—weak layer instability.The paper correspondingly proposes a large-area continuous undercutting stress migration control technology and a differentiated reinforcement precision support technology centered on high-strength mechanized wet shotcrete.Since the promotion of stability control technology,the surrounding rock of the undercutting roadway has become unstable phenomenon has been significantly reduced,the annual deformation rate of surrounding rock has been reduced by 50 %,and the roadway repair rate has been lowered from 20 % to 5 %,which provides engineering reference for the precise control of roadway surrounding rock under complex structural conditions in similar metal mines.