Self-examination packer

The invention provides a self-examination packer. The self-examination packer can serve as a sieve tube hanger, and can also be used for blocking bottom water in a layered bottom-sealing and top-extraction process. An examination through hole is formed in a side wall of an upper center tube of the self-examination packer; an examination piston which is used for sealing the examination through hole is arranged in the upper center tube through an examination shear pin; examination spacer rings are arranged between adjacent rubber barrels; a plurality of radial fluid through holes are formed in the periphery of each examination spacer ring; and the side wall of a core tube of each rubber barrel is provided with a second through hole which can be connected with the corresponding radial fluid through hole after the rubber barrel is compressed. After setting is finished, the examination shear pin is shorn off through liquid pressure, and pressure liquid enters a gap between the two adjacent rubber sleeves through a liquid channel so as to judge whether setting is complete or not. Moreover, the self-examination packer also comprises a midway-dropping-preventing mechanism and an elastic unsealing mechanism; the midway-dropping-preventing mechanism comprises an upper joint and a limiting pawl spring; and the elastic unsealing mechanism comprises a lower center tube and an unsealing nut.