Underwater mechanical arm centering device

The invention discloses a centering device for an underwater mechanical arm. The centering device comprises a base, a sealing sleeve and a flexible framework, wherein the base is used for being in butt joint with the underwater mechanical arm; the sealing sleeve is used for being centered with a working hole site and being in sealing sleeving connection with the working hole site and can be tensioned; the sealing sleeve is arranged on the base, and the flexible framework is arranged on the base and is supported on the periphery of the sealing sleeve; the end part, back on to the base, of the flexible framework protrudes out of the corresponding end part of the sealing sleeve to form a positioning end which is preliminarily aligned with a working hole site; the base is provided with a through hole, and the through hole is communicated with an inner channel of the sealing sleeve to form a sealing channel communicated with the underwater mechanical arm. According to the centering device for the underwater mechan