When　chaotic　oscillator　changing　from　chaotic　state　to　large-scale　periodic　state,　its　phase　diagram　symmetry　will　obviously　changed.　Hu　invariant　moment　is　adopted　to　describe　the　different　state　of　chaotic　oscillator　phase　diagram.　The　threshold　value　of　chaos　oscillator　under　the　large-scale　periodic　state　is　ascertained　by　the　curve　of　invariant　moment-periodic　driving　force.　According　to　the　difference　of　Hu　invariant　moment　value　for　different　chaotic　oscillator　phase　diagram,　the　state　of　chaos　oscillator　can　be　automatically　identified.　Finally,　the　simulated　and　engineering　vibration　signals　are　analyzed,　and　the　results　show　that　invariant　moment　can　accurately　identify　the　state　of　chaotic　oscillator　and　have　better　noise-tolerance.