Underground ratchet type blanking plug

The invention belongs to the technical field of oil and gas equipment, and discloses an underground ratchet type blanking plug which comprises a clamping working barrel, the clamping working barrel is connected with an oil pipe, two floating ratchet clamping blocks are oppositely arranged in the clamping working barrel, the lower end of the clamping working barrel is in threaded connection with a clamping connector, and the upper end of the clamping connector abuts against the floating ratchet clamping blocks; a V-shaped sealing ring is annularly arranged in the middle of the blocking rod, and a fixed ratchet matched with the floating ratchet clamping block is arranged on the lower portion of the blocking rod. According to the underground ratchet type blanking plug, the clamping working barrel is connected to the bottom of the oil pipe in advance, when the oil pipe needs to be replaced subsequently, a feeding tool is put into the plugging rod, the plugging rod is connected with the clamping working barrel, th