Weak signal which is submerged by strong noise in.engineering is difficult to detect accurately. The bistable stochastic.resonance (BSR) system is proposed in this paper to detect the weak.signal. And some simulation researches, including single frequency.signal stochastic resonance detection; multi frequency signal.stochastic resonance detection and multistage stochastic resonance.detection, are accomplished. Simulation results showed that the BSR.system can effectively improve the signal to no