An electrically-adjustable tool holder precisely movable in a straight line within a magnetic field under electrical stimulation includes a handle body, a connecting member, and a driving member. The connecting member has a first end securely coupled to an end of the handle body, a second end opposite to the first end, and defines a through hole passing through the first end and the second end. The driving member includes a magnet securely received in the through hole, and an electrical electric coil movably received in the magnet. The electric coil is configured to be securely coupled to the tool, and moves the tool up or down along the central axis of the handle body.