The chaotic characteristic of intermittent chaotic model——Duffing oscillator is analyzed,the nonequilibrium phase change of oscillator is sensitive to small signal and immune against white noise and the periodic interfering signal having larger angular frequency difference to the referential signal.The chaotic oscillator array is applied to detect weak signal in noise background,and Melnikov method is adopted as chaotic criterion which is easy to be directly calculated.The simulation results indicate this d...