Step-by-step releasable packer

The utility model relates to a stage by stage unsealing packer which is mainly used for ordinary mechanical release multi-stage water plugging pipe columns and is composed of an upper contact, an upper piston, an upper piston sleeve, an upper lock sleeve, an upper lock ring seat, a central pipe, a lower piston, an outer central pipe, a rubber barrel, a leather cup upper steel sleeve, a switch piston, a middle steel sleeve, a pressure difference piston, a lower steel sleeve, an upper claw, a lower claw, a lower contact, etc. The utility model realizes hydraulic setting, hydraulic seal inspection and stage by stage unsealing through lowering and lifting a pipe column. The utility model with simple operation can be used for hydraulic setting, unsealing through lowering and lifting a pipe column, and stage by stage unsealing for multi-stage use. The stage by stage unsealing packer solves the problem of difficult unsealing for multi-stage use and difficult seal inspection for multi-stage use if a similar packer is used and enhances the successful plugging rate of water plugging pipe columns.