Oil field underground casing packer

The utility model discloses an oil field underground casing packer which comprises a casing, a central pipe is connected in the casing in a sliding mode, penetrating and pressing holes are formed in the casing and the central pipe, a setting ball seat is arranged in the central pipe, a sealing cover is fixed to the position, close to the lower end, of the central pipe, the sealing cover is connected with a rubber seat through a reset spring, and the rubber seat is fixedly connected in the casing. A plurality of fixing seats are fixed to the outer sides of the two ends of the sleeve and slidably connected with sliding frames, one ends of the sliding frames are connected with supporting springs, the other ends of the sliding frames are rotatably connected with rolling wheels, a middle rubber pipe is arranged in the middle of the sleeve, a plurality of fixing rings are fixed to the outer side of a central pipe, and a plurality of first connecting rods and second connecting rods are hinged to the outer sides of t