An all-optical information exchange device and method are provided. The all-optical information exchange device includes: 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; the first optical filter is transmissive to a first wavelength/waveband signal light, and the second optical filter is transmissive to a second wavelength/waveband signal light during use.