Abstract: An adjustment device for adjusting a torque of a torque wrench includes a base unit, a driving unit, and a control unit. The torque wrench includes a shank body extending along an axis, an adjusting unit threadedly engaging the shank body, and a resilient member abutting against the adjusting unit. The base unit is for mounting of the torque wrench. The driving unit includes a coupling member removably connected to the adjusting unit, and a driving motor. The control unit controls the driving motor to drive rotation of the coupling member about the axis for driving rotation of the adjusting unit to thereby move the adjusting unit along the axis to vary a preload force of the resilient member and thus a torque of the torque wrench and to move the adjusting unit to a position where the torque of the torque wrench corresponds to a predetermined torque value.