The invention discloses an optical detector based on two-dimensional stratiform atomic crystal materials. The optical detector comprises a silicon substrate coated with silica, a first graphene conducting layer, a two-dimensional stratiform atomic crystal semiconductor material layer and a second graphene conducting layer are sequentially coated on the silicon substrate coated with the silica in a superposition mode, and the first graphene conducting layer and the second graphene conducting layer respectively form heterogeneous structures with the two-dimensional stratiform atomic crystal semiconductor material layer. One end of the first graphene conducting layer and one end of the second graphene conducting layer are provided with a first electrode layer and a second electrode layer respectively, and the first electrode layer and the second electrode layer have no any overlapping, and the first electrode layer and the second electrode layer are arranged outside an overlapping area of the first graphene conducting layer, the second graphene conducting layer and the two-dimensional stratiform atomic crystal semiconductor material layer at the same time. A passivation layer is respectively arranged above each layer. The optical detector based on the two-dimensional stratiform atomic crystal materials utilizes the two-dimensional stratiform atomic crystal materials, has the operating characteristics that detection spectrum range is wide, response speed is fast and cut-off frequency is high, and has the characteristics that spectral responsivity of a device is high and extraction of a photon-generated carrier is simple.