The photo-detachment cross section of H- near two parallel elastic interfaces is derived and calculated by using the closed orbit theory. The photo-detachment cross section of H- near two interfaces is shown to exhibit multi-periodic oscillations when the distance between the H- and the interface is varied. Each peak in the Fourier transformed photo-detachment cross section corresponds to the length of a closed orbit, which is quite similar to the case of atomic spontaneous emissions in a dielectric slab. This study provides a new understanding of the photo-detachment process of H- in the presence of interfaces.