The invention provides a graphene light detector based on a metamaterial structure and relates to a light detector. The graphene light detector based on the metamaterial structure can achieve ultra-wide-band absorption. The graphene light detector is of a laminated structure and includes a metal layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer, a graphene layer, a medium layer and a graphene layer in sequence from top to bottom in the vertical direction. In the horizontal direction, the graphene layers and the medium layers are grid-shaped strips, the strips are arranged cyclically, and bias voltage is added for each graphene layer and used for changing the refractive index of graphene so as to dynamically regulate and control the spatial refractive index of each graphene layer and further adjust the spatial absorptivity of the whole structure.