Plugging structure of subway station bottom plate dewatering well casing and using method of plugging structure

The invention discloses a plugging structure of a subway station bottom plate dewatering well casing and a using method of the plugging structure. The plugging structure comprises a pull rod, the upper end of the pull rod is a first connecting end provided with an external thread, the first connecting end is connected with a first nut, and the bottom of the pull rod is provided with a positioning mechanism; a circular truncated cone embedded block is movably arranged on the pull rod in a sleeving mode, the bottom of the circular truncated cone embedded block abuts against the top of the positioning mechanism, and the diameter of the circular truncated cone embedded block is gradually increased from top to bottom; an elastic rubber block is cylindrical, the elastic rubber block is movably arranged on the pull rod in a sleeving mode and located at the top of the circular truncated cone embedding block, and a groove matched with the upper end of the circular truncated cone embedding block is formed in the bottom