The method for shaping a hexagonal tool of the present invention includes the following steps: preparing a hexagonal rod having an axis and a bottom, which has a periphery; fixing the hexagonal rod on a lathe, the lathe having a clamp and a lathe tool, the hexagonal rod being clamped and rotated about the axis by the clamp, the lathe tool lathing the hexagonal rod in a single operation to form a neck portion on the hexagonal rod, a driving head being defined on the hexagonal rod between the neck portion and the bottom; and lathing a rounding edge around the periphery of the bottom by the lathe tool. As such, a hexagonal tool having a neck portion and a driving head is thus quickly formed.