Replaceable sealing structure at joint of underground concrete structure

The invention relates to a replaceable sealing structure at a joint of an underground concrete structure. The sealing structure at the joint comprises an elastic inflation piece, an enclosure plate, an inflation piece groove and an inflation connector, wherein the inflation connector is used for inflating the elastic inflation piece; an air cavity is formed in the center of the elastic inflation piece, and the elastic inflation piece is arranged in the inflation piece groove; the inflation piece groove is formed between two butt joint faces on the outer side of the joint, the enclosure plate covers the inflation piece groove in an enclosure mode to form an inflation piece channel, the elastic inflation piece is matched with the inflation piece channel, and the outer edge of the elastic inflation piece is attached to the interior of the inflation piece channel; and air is inflated into the air cavity of the elastic inflation piece through the inflation connector, so that the elastic inflation piece elastically