The invention discloses a concrete double-mold structure for the top surface of a building, and relates to the technical field of supporting molds for the top surfaces of buildings. The concrete double-mold structure for the top surface of the building comprises a lower assembly plate, an upper assembly plate and a ring beam supporting frame, wherein the lower assembly plate is formed by multiple lower template units which are assembled in the ring beam supporting frame; the upper assembly plate is formed by assembling multiple unit surface molds; the ring beam supporting frame is formed by fixing a rectangular bottom frame and four side templates perpendicularly surrounding the rectangular bottom frame; the left end part and the right end part of the rectangular bottom frame are both provided with long strip-shaped bonding grooves; the upper ends of the four corners of the ring beam supporting frame are all fixedly provided with fixing blocks; the upper ends of the upper assembly plate are all fixedly provided with regulating blocks; the regulating blocks are all perpendicularly and fixedly provided with tension screw rods; the regulating blocks are all connected with the fixing blocks on the corresponding same sides through the tension screw rods. An integral assembly structure is adopted for the concrete double-mold structure for the top surface of the building; the pouring flatness is high; the thickness is uniform; the construction difficulty can be decreased.