In the wireless communications system,the cooperation of users with eavesdropping relay may result in the leakage of information.To ensure their communication security,it's necessary to pay the cooperative jammer for the jamming power.In order to improve the user benefits under secret communication,this paper presents a power allocation mechanism combining relay with jammer based on the Stackelberg game.In the case of the eavesdropping relay cooperative forwarding and the idle user collaboratedinterfering,a tripartite game model is established based on Stackelberg game,where the communication user is regarded as a power-buyer and the relay and idle users are regarded as power-sellers.Simulation results show that the proposed joint power allocation mechanism will converge to some value which is not only the maximum utility of all nodes after several iterations,but also the maximum security capacity of the sender.The security capacity improves by 0.2 (bit·s-1) ·Hz-1 than that of relay with full power,which improves the safety performance of the user.