The utility model provides a fish reef type offshore wind power erosion-preventing pile foundation and belongs to the technical field of ocean engineering technologies. The fish reef type offshore wind power erosion-preventing pile foundation comprises a pile leg, a guide plate, a spring, fish reef type dump-filled blocks, stainless steel rods and a sleeve, wherein the pile leg is inserted into a seabed soil layer and sleeved by the guide plate and the sleeve, multiple fish reef type dump-filled blocks are arranged around the sleeve and connected with the sleeve through springs, and a circle of stainless steel rods is arranged around the fish reef type dump-filled blocks. The sleeve is in a shape of a circular truncated cone, and a surface layer is full of honeycomb holes. The fish reef type dump-filled blocks are of regular hexahedron structures and are hollow, and surface layers are full of through holes. The problem of wind power based erosion maintenance can be solved by means of the fish reef type offshore wind power erosion-preventing pile foundation, an artificial fish reef for providing a habitat for fish can be also formed, and two purposes are achieved in one.