Two single bistable systems were constituted into a coupling system by means of nonlinear coupling. One of the bistable systems was considered as controlled system with fixed parameters, and the other as control system with adjustable parameters. Adjusting the coupling coefficients and parameters of the control system can produce stochastic resonance. With a single-frequency signal added to the control system, changing the signal frequency can produce the resonance. Due to the effect of coupling, the resonance of control system will affect the stochastic resonance of the controlled system, and the dual-resonance phenomenon happens in the coupled system, which realizes the usage of one resonance to influence another and make the stochastic resonance of controlled system more intense. This also has been verified using computer simulation.