The utility model relates to a shell reef capable of providing a better flow field effect. The shell reef comprises a hollow cuboid frame, wherein a stream guidance hole penetrating through front and back end faces of the cuboid frame is formed in the cuboid frame, and a space defined by the periphery of the stream guidance hole and the cuboid frame is filled with shells, so that the upper end face of the cuboid frame is covered by the shells. According to the shell reef, the stream guidance hole penetrating front and back is beneficial for seawater to run through a reef body more thoroughly during flux and reflux, the water permeability of the reef body is increased, stronger rising flow can be generated by putting the shell reef in the sea, the shell reef can generate a back eddy area with larger span in the sea, and thus a flow field effect generated by the reef body is enhanced; after the shell beef is put, the lower end face of the shell beef is sunken into a seabed, is obstructed by seabed materials and cannot be pervious to water, so the upper end face of the cuboid frame does not need permeable holes and can be filled with the shells directly, and thus the reef body is simple in structure and easy to construct; the shell reef can be applied to aquaculture.