The stochastic resonance (SR) in coupled underdamped bistable systems induced by dichotomous noises is studied in this paper. Firstly, the effect of noise parameter on the system output is analyzed. For large noise intensity, the hopping of the particles between two potential wells is observed. In addition, with the increasing noise intensity, the switching between the two wells is found to increase. Finally, the effect of noise on the output power spectrum and spectral power of the system are characterized. It is found that the power spectrum of the system at some noise intensity has a sharp peak, and the peak value is maximized at a critical value of noise intensity. In particular, for different parameters, a nonmonotonic behavior of signalnoiseratio (SNR) is shown. And the optimum system parameter is found where the SNR peak value reaches a maximum.