A living body identification device for identifying characteristic information of a living body, comprising an acquisition unit and a processing unit, wherein, the acquisition unit is configured for emitting light towards a characteristic position of the living body and receiving light reflected from the characteristic position, then converting the received light into an electrical signal, and sending the electrical signal to the processing unit; and the acquisition unit comprises at least one light source and a plurality of photosensitive elements which are disposed at intervals; and the processing unit is configured for generating an image of the characteristic position according to the electrical signal, and processing the image of the characteristic position to eventually obtain the characteristic information of the characteristic position, the characteristic information being used for uniquely identifying the living body, wherein the acquisition unit comprises a transparent substrate and a plurality of light sources and a plurality of photosensitive elements arranged on a surface of the transparent substrate at one side, the light sources being configured for emitting light towards the characteristic position, the photosensitive elements being configured for receiving the light reflected from the characteristic position and converting the received light into an electrical signal; and the plurality of light sources are distributed at intervals, and the plurality of photosensitive elements are arranged in spaces between the light sources, wherein the plurality of light sources are uniformly distributed, and the plurality of photosensitive elements are uniformly distributed, wherein the plurality of light sources are arranged in a matrix, and the distances between the photosensitive elements and the light sources adjacent to the photosensitive elements are identical, characterized in that the plurality of photosensitive elements are each located in a space between any two light sources which are adjacent in diagonal direction, or in that the plurality of photosensitive elements which are integrally connected are arranged in the space between the plurality of light sources. the acquisition unit is configured for emitting light towards a characteristic position of the living body and receiving light reflected from the characteristic position, then converting the received light into an electrical signal, and sending the electrical signal to the processing unit; and the acquisition unit comprises at least one light source and a plurality of photosensitive elements which are disposed at intervals; and the processing unit is configured for generating an image of the characteristic position according to the electrical signal, and processing the image of the characteristic position to eventually obtain the characteristic information of the characteristic position, the characteristic information being used for uniquely identifying the living body, wherein the acquisition unit comprises a transparent substrate and a plurality of light sources and a plurality of photosensitive elements arranged on a surface of the transparent substrate at one side, the light sources being configured for emitting light towards the characteristic position, the photosensitive elements being configured for receiving the light reflected from the characteristic position and converting the received light into an electrical signal; and the plurality of light sources are distributed at intervals, and the plurality of photosensitive elements are arranged in spaces between the light sources, wherein the plurality of light sources are uniformly distributed, and the plurality of photosensitive elements are uniformly distributed, wherein the plurality of light sources are arranged in a matrix, and the distances between the photosensitive elements and the light sources adjacent to the photosensitive elements are identical, characterized in that the plurality of photosensitive elements are each located in a space between any two light sources which are adjacent in diagonal direction, or in that the plurality of photosensitive elements which are integrally connected are arranged in the space between the plurality of light sources.