The invention relates to a locking device. The locking device comprises a lock body, a plurality of clamping jaws, a plurality of elastic parts and a drive rod assembly; the lock body is columnar, a plurality of sliding grooves distributed around the axis of the lock body are formed in the first end of the lock body, and a boss is arranged at the second end of the lock body; the clamping jaws and the corresponding elastic parts are arranged in the corresponding sliding grooves, the elastic parts are used for drawing the clamping jaws in through springback, the drive rod assembly penetrates the lock body in the axis direction of the lock body, is exposed out of the first end of the lock body and is rotatably fixed to the lock body, the sliding grooves are arranged in an inclined manner relative to the axis of the lock body, the drive rod assembly can drive the multiple clamping jaws to move towards the boss and expands outwards, or the multiple clamping jaws are affected by the corresponding elastic parts to move towards the direction opposite to the boss and be drawn in. The locking device can firmly and reliably lock a table board of a computer table to an upper support, and use is easy and convenient.