Slipping mechanism and seat headrest thereof

The invention discloses a slipping mechanism which comprises a body, the body comprises a transmission gear and an adjusting rod, the transmission gear is connected to the adjusting rod in a sleeving mode, a first abutting block and a second abutting block are arranged at the two ends of the adjusting rod respectively, an elastic piece is arranged between the transmission gear and the second abutting block, and one end of the elastic piece abuts against the transmission gear; one end of the elastic piece abuts against the first abutting block, the other end of the elastic piece abuts against the second abutting block, a circular-truncated-cone-shaped protrusion is arranged at the joint of the transmission gear and the first abutting block, and a circular-truncated-cone-shaped groove matched with the circular-truncated-cone-shaped protrusion is formed in the first abutting block. The adjusters comprise slipping mechanisms, and the driving device drives the two adjusters at the same time through the transmissio