A blade sharpening tool includes a main body, a first grinding unit, a second grinding unit, and a protective jacket. The first grinding unit is directed toward a direction in line with the axial direction of the main body. Thus, when the first grinding unit is pressed to move on the blade of the gardening shears, the first grinding unit is movable in the direction the same as that of the blade, so that the first grinding unit is operated easily and quickly to facilitate the user operating the blade sharpening tool in an energy-saving manner. In addition, the mating surface of the main body has a shape corresponding to that of the jaw of the gardening shears to facilitate movement of the first grinding unit on the blade.
