A pruning hook includes a fixed seat, a cutter pivotally mounted on the fixed seat, a link connected with the cutter, a drive arm pivotally mounted on the fixed seat and connected with the link, a pull cord connected with the drive arm, and a restoring spring biased between the fixed seat and the drive arm. The cutter has a sliding slot provided with a plurality of locking teeth. A driving bolt secured on the link is movable in the sliding slot and is detachably locked onto one of the locking teeth. Thus, when the pull cord is pulled and slightly loosened in a staggered manner, the driving bolt is driven to engage each of the locking teeth to drive the cutter to pierce an object step by step, so that the cutter can shear the object in a multi-stage manner.
