The invention provides a headlamp steering system and a steering control method thereof. The method comprises the following steps: reading a road image in front of a vehicle, identifying at least one lane line and a first previewing point, setting a second previewing point on the lane line after a continuous time, calculating an angle between the first and second previewing points, and changing the direction of a headlamp so that the first previewing point shifts along with the second previewing point and is overlapped with the second previewing point and changed along with the lane line, equivalently, the headlamp changes the irradiation direction along with the curvature of the road so as to expand the visible range when a driver passes through a curve.