A method, apparatus and optical device for detecting a relationship between an evanescent field and Goos-Hänchen shift, said method comprising: obtaining a potential field function of an evanescent field acting on total-reflection light according to physical meanings of a force function and the potential field function of light in the evanescent field (S101); obtaining a wave function of the perturbed total-reflection light by means of the Schrödinger equation by combining with the potential field function of the evanescent field acting on total-reflection light (S102); and comparing the wave function of the perturbed total-reflection light with a wave function of free total-reflection light with no action from the evanescent field, and determining a momentum gained by the total-reflection light under the action of the evanescent field, which is the same in nature as a momentum of the evanescent field (S103).
