Abstract: In order to obtain stress characteristics of rock bolt thread end,this paper used numerical simulation software to research the stress distribution features of rock bolt thread end under the different single and composite stress conditions of pull,torsion,bend and shear. The results showed that rock bolt thread end stress ch aracteristics was very complicated under different stress condition,thread bottom appeared different degree of stress concentration effect,the bending angle had an sign ificant impact on rock bolt thread end,larger bending angle had a bad influence for thread stress. Compare to tensile stress ,the torsion stress had more significant impa ct on thread stress of rock blt,the accurate control of torque could avoid rock bolt from undertaking bigger stress.