Two bistable systems can become multistable through nonlinear coupling. The coupled system is more valuable than the single bistable system in theoretical research and practical application. The response characteristics of the coupled system subjecting to noise and periodic signal have been analytically analyzed to show the effect of coupled coefficient and bistable system parameters on stochastic resonance. The results show that the stochastic resonance is produced by the effect of zonal double-well potential. The schematic diagram of feedback coupled control principle has also been constructed. The method gives a reliable theoretical basis for artificially producing stochastic resonance or strengthening the effect of resonance in bistable system to control the stochastic resonance, and also for its application. The results of numerical simulation agree with that of theoretical analysis.