Fixing device for bolt-hole-free flange

The utility model belongs to the technical field of nuclear power, and particularly relates to a fixing device for a bolt-hole-free flange. A plurality of nuts are arranged on the outer side wall of a frame of an annular structure and used for fixedly connecting the frame to a preset fixed position; the plurality of pull rods are in threaded connection with the frame, and the distance between a convex part at the top end of each pull rod and the upper surface of the frame can be adjusted by rotating each pull rod; the buffer plate is fixedly arranged on the inner side wall of the frame, the multiple sliding blocks are slidably connected to the side face of the frame, a mechanical device needing to be overturned can be placed in the frame, the mechanical device can be adjusted to the center position of the frame by adjusting the multiple sliding blocks, the mechanical device is fixed in the radial direction, and the mechanical device can be overturned by adjusting the heights of the multiple pull rods. The fla