A prefabricated annular frame structure for the opening of a fabricated underground structure comprises a prefabricated rectangular annular frame, and the four sides of the prefabricated rectangular annular frame are provided with tenons or mortises connected with non-standard prefabricated components and standard prefabricated components at the four sides. Auxiliary connection bolts are disposed on two sides of the prefabricated rectangular annular frame. Embedded bar connectors or embedded steel bars are disposed on one or two sides of the prefabricated rectangular annular frame. Grouting holes are arranged on one side of the plane of the prefabricated rectangular annular frame. A waterproof sealing groove is arranged at the four sides of the plane of the prefabricated rectangular annular frame. The beneficial effects of the prefabricated annular frame structure are that impairment of a main body structure by other opening methods can be effectively reduced, the problem that opening construction difficulties and risks of conventional prefabricated shield segments are large is solved, connection between the prefabricated rectangular annular frame structure and adjacent prefabricated components is reliable and controllable, the waterproof effect is excellent, the construction is convenient, deformations of the structure and stratums can be well controlled, and stability and security of a structural system in the construction phase are ensured.