A quick locking device having a fixing mount; a fixed pressing groove and a movable pressing groove arranged opposite thereto on the fixing mount; a pulling rod connected to the fixed pressing groove and the movable pressing groove, so as to adjust the opening and closing of the movable pressing groove; a pivot shaft; a cam lever pivotally connected to the pulling rod through the pivot shaft, so as to adjust the opening or closing distance between the fixed pressing groove and the movable pressing groove; and a rotational positioning locking mechanism installed in the cam lever, wherein the rotational positioning locking mechanism comprises a positioning groove formed on the pivot shaft, a positioning member arranged in the cam lever and movably engaged with the positioning groove, and a locking operation member controlling the movement of the positioning member.