<p>A blade control system, comprising: an angle acquisition unit that obtains an angle relative to a lift frame design surface; a degree-of-opening determination unit that determines the degree of opening on the basis of the angle; and a lift cylinder control unit that raises the blade by opening a proportional control valve in accordance with the degree of opening, in the event that the distance between the design surface and the edge of the blade is no more than a threshold value.</p>
