Abstract: The pressure balancing device comprises a housing, a deformation medium accommodated in the housing and capable of deforming under compression, and a sealing member movably connected with the housing and capable of deforming under pressure. When part of the deformation medium is compressed by the sealing member, the deformation medium deforms so that a part, not compressed, of the deformation medium compresses a corresponding part of the sealing member to make it protrude outwards. The pressure balancing device is simple in structure, easy to assemble and convenient to operate, and raw material cost and processing cost are saved a lot.