Disclosed are a lawn mower robot and a control method thereof. The control method includes sensing whether or not an obstacle is present during driving at a normal velocity, decelerating the lawn mower robot, when the obstacle is sensed, sensing whether or not the lawn mower robot collides with the obstacle in the decelerated state, and differently driving the lawn mower robot if a collision of the lawn mower robot with the obstacle is sensed and if a collision of the lawn mower robot with the obstacle is not sensed.