The invention discloses a pivot and a pivot sleeve structure thereof which are positioned by a locking pin on a frame provided with a first locating hole and a second locating hole for locking a bayonet baffle plate of a function extension card. The invention comprises a pivot base and a pivot sleeve. The top of the pivot sleeve being pressed, a grab of the pivot sleeve slide out of a grab groovepositioned on the pivot base under the guide a protruding block, thereby the pivot sleeve is easy to be detached form the pivot sleeve, without any assistant tool, thereby solving the problems existing in the prior art.