An all-optical information exchange device, at least comprising: a second-order nonlinear optical waveguide, a first optical coupler, a third optical coupler, a fourth optical coupler, a first optical filter, a second optical filter and a first polarization controller, wherein, a first port of the polarization controller is configured to be an input port for a WDM signal light, and a second port of the polarization controller is connected to a first port of the first optical coupler; a second port of the first optical coupler is configured to be an output port for the WDM signal light, a third port of the first optical coupler is connected to a first port of the first optical filter, and a forth port of the first optical coupler is connected to a first port of the second optical filter; a second port of the first optical filter is connected to a first port of the third optical coupler, and second port of second optical filter is connected to a first port of the fourth optical coupler; a first port of the second-order nonlinear optical waveguide is connected to a third port of the third optical coupler, a second port of the second-order nonlinear optical waveguide is connected to a third port of the fourth optical coupler; a second port of the third optical coupler and a second port of the fourth optical coupler are configured to be input ports for a control light respectively; and the WDM signal light comprises a first wavelength/waveband signal light and a second wavelength/waveband signal light, the first optical filter is transmissive to the first wavelength/waveband signal light, and the second optical filter is transmissive to the second wavelength/waveband signal light during use. a second-order nonlinear optical waveguide, a first optical coupler, a third optical coupler, a fourth optical coupler, a first optical filter, a second optical filter and a first polarization controller, wherein, a first port of the polarization controller is configured to be an input port for a WDM signal light, and a second port of the polarization controller is connected to a first port of the first optical coupler; a second port of the first optical coupler is configured to be an output port for the WDM signal light, a third port of the first optical coupler is connected to a first port of the first optical filter, and a forth port of the first optical coupler is connected to a first port of the second optical filter; a second port of the first optical filter is connected to a first port of the third optical coupler, and second port of second optical filter is connected to a first port of the fourth optical coupler; a first port of the second-order nonlinear optical waveguide is connected to a third port of the third optical coupler, a second port of the second-order nonlinear optical waveguide is connected to a third port of the fourth optical coupler; a second port of the third optical coupler and a second port of the fourth optical coupler are configured to be input ports for a control light respectively; and the WDM signal light comprises a first wavelength/waveband signal light and a second wavelength/waveband signal light, the first optical filter is transmissive to the first wavelength/waveband signal light, and the second optical filter is transmissive to the second wavelength/waveband signal light during use.