The paper, we put forward a new piecewise hybrid system, and study the behavior of the stochastic resonance. Through the method of numerical simulation, we studied the influence of noise and parameters variation to the output of the system, and also calculated the behavior of error rate against system parameters. The result showed that with the appropriate system parameters, the system can restore the input signal well from the noise, and can detect the binary aperiodic signal under the strong noise background.