The invention discloses a beam imaging device, which comprises a graph layer, a transition layer and a cladding layer, wherein the transition layer and the cladding layer are symmetrically stacked onboth sides of the graph layer in sequence; and the refractive indexes of the graph layer, the transition layer and the cladding layer are reduced in sequence. According to the beam imaging device disclosed in the invention, the transition layer and the cladding layer are symmetrically stacked on both sides of the graph layer in sequence, the refractive index of the graph layer is larger than thatof the transition layer adjacent to the graph layer, the refractive index of the transition layer is larger than that of the cladding layer, the graph layer has the largest graph layer, the transitionlayer and the cladding layer execute multiple restrictions on light waves transmitted in the graph layer, transmission of the light waves in the graph layer can be effectively restricted, the transmission loss is reduced, and the light transmission efficiency is improved.