Sealing structure of underwater mechanical arm

The utility model relates to the technical field of underwater mechanical arm protection, in particular to a sealing structure of an underwater mechanical arm, which comprises a mounting plate, a protective tube and a mechanical arm, the inner side of the lower port of the protective tube is in threaded connection with a sealing cylinder, and the inside of the sealing cylinder is in sliding connection with a movable part. The movable component is composed of an annular plate, a sealing plate, a sealing gasket, a connecting column, a clamping spring piece and a limiting plate, the sealing gasket is bonded to the plate face, facing the sealing cylinder, of the sealing plate, and the side, away from the connecting column, of the sealing plate is fixedly installed on the annular plate. The sealing performance can be further improved through the design of the sealing cylinder connected in a threaded mode, convenience is provided for follow-up maintenance work of the mechanical arm through the telescopic movable pa