Piston sealing structure and piston type buoyancy regulator

The invention provides a piston sealing structure and a piston type buoyancy regulator, and belongs to the field of buoyancy regulators, the piston sealing structure comprises a sealing ring I, a sealing ring II and an oil bag, and the sealing ring I and the sealing ring II are arranged on a piston at an interval; the oil bag is arranged in the piston and used for filling the gap between the sealing ring I and the sealing ring II with lubricating oil. The piston type buoyancy regulator comprises a watertight pressure-resistant cabin, a piston arranged in the watertight pressure-resistant cabin and the piston sealing structure. The sealing ring I and the sealing ring II can seal the water side and the air side respectively, and the sealing effect is good; the gap between the sealing ring I and the sealing ring II is filled with lubricating oil through the oil bag, the sealing effect can be further improved, the filled lubricating oil can enhance the lubricating performance of piston movement in the piston movi