The invention discloses a deep-sea
sediment core pressure-maintaining device matched with a
submarine drilling rig and a method for using the deep-sea
sediment core pressure-maintaining device. The deep-sea
sediment core pressure-maintaining device comprises an upper seal cover, a
metal hollow drilling rod, a sampling tube and a lower seal cover, wherein the sampling tube is arranged in the
metal hollow drilling rod; the
metal hollow drilling rod is connected with the upper seal cover and the lower seal cover by fine threads; the upper seal cover and the lower seal cover respectively comprise an inflation valve, a top cover, a pressure shell, an expandable
air cushion and O rings; the top cover and the expandable
air cushion are arranged in the pressure shell; the O rings are arranged between the pressure shell and the top cover and between the pressure shell and the expandable
air cushion; and the inflation valve is arranged on the top cover. The deep-sea sediment core pressure-maintaining device is matched with the
submarine drilling rig, can maintain in-situ pressure in the process of extracting deep-sea sediments from a sea
bed to a sea surface, and can guarantee non-loss of
hydrocarbon gas such as
methane gas and non-melting of a
hydrate. The invention is applied to drilling and
coring ocean sediments by using the
submarine drilling rig and can be widely applied to exploration of ocean resources such as the
hydrate and deep-sea oil and gas resources.