讨论了小信号摄动的受迫Duffing振子在非平衡相变临界点附近的行为,推导出振子发生相变的相位条件,得出在该临界点附近相变对小信号敏感的结论.推导出系统发生间歇混沌现象的频差条件,该临界点附近的微小频差是产生间歇混沌的原因,这是与切分岔概念不同的产生间歇混沌的又一机理. The behavior of the forced Duffing oscillator with small signal perturbation around the critical point of unbalanced phase transition is discussed, and the phase condition of the oscillator phase transition is deduced. The conclusion is drawn that the phase transition is sensitive to small signal near the critical point. The frequency difference condition of the intermittent chaos phenomenon occurs in the system. The tiny frequency difference around the critical point is the reason for the intermittent chaos, which is another mechanism of intermittent chaos with the concept of bifurcated bifurcation.