The invention discloses a spherical surface flat hinge. The spherical surface flat hinge mainly comprises an upper flat hinge body, a lower flat hinge body and pin shafts. The lower surface of a steel plate of the upper flat hinge body is a convex spherical surface. The upper surface of a steel plate of the lower flat hinge body is a concave spherical surface, the other side is a plane, and shearing nails are arranged on the upper plane of the upper flat hinge body and the lower plane of the lower flat hinge body. The concave spherical surface of the lower flat hinge body is provided with a groove, and sliding sheets are distributed in the groove. Circular holes are formed in the center of the upper flat hinge body and the center of the lower flat hinge body, sleeves are arranged in the center of the upper flat hinge body and the center of the lower flat hinge body, the upper flat hinge body is arranged above the lower flat hinge body, the upper flat hinge body and the lower flat hinge body are connected through the circular holes penetrating through the upper flat hinge body and the lower flat hinge body and the pin shafts of the sleeves, and the bottoms of the pin shafts are embedded in concrete in front of a rotating body. By means of the spherical surface flat hinge, the requirement for the heavy rotating body construction method can be met, producing and manufacturing are convenient, and the construction method is flexible.