A method for detecting a road edge, the method comprising the steps of: obtaining a disparity map with a road region and a corresponding V-disparity map; extracting, from the V-disparity map, a road line Lv; obtaining, based on points having a height less than a predetermined height threshold above the road line Lv extracted from the V-disparity map, a sub-U-disparity map with the road; wherein a sub-U-disparity map relates to a part of the U-disparity map relating to the road; obtaining, from the V-disparity map, points below the extracted road line Lv with a distance from a camera for picking up the disparity map that is less than a predetermined distance threshold; extracting, from the disparity map, points that correspond to the points obtained from the V-disparity map; projecting the points extracted from the disparity map onto the sub-U-disparity map as reliable road points; extracting, from line segments obtained by a straight line fitting based on the reliable road points, road edge line segments that satisfy a predetermined road edge condition from the sub-U-disparity map, wherein the predetermined road edge condition includes the following: the sum of the absolute value of a horizontal and vertical intercepts of such a line segment, is the minimum value from all of the line segments; and the real length corresponding to the line segment in a real-three-dimensional world coordinate system is greater than a predetermined length threshold; wherein the horizontal intercept is the intersection between a straight line corresponding to such a line segment and the horizontal axis; and the vertical intercept is the intersection between a straight line corresponding to such a line segment and the vertical axis; extracting the road edge from the sub-U-disparity map, by; calculating an end point of an extracted road edge line segment when a road edge line segment is extracted, determining a region of interest for extracting the next road edge line segment by setting an angle change range based on the angle of the extracted road edge line segment and a region in an angle change range, and extracting the next road edge line segment with a start point that is the calculated end point from the region of interest; and repeating the process of extracting the road edge line segment, until no road edge line segment can be extracted. obtaining a disparity map with a road region and a corresponding V-disparity map; extracting, from the V-disparity map, a road line Lv; obtaining, based on points having a height less than a predetermined height threshold above the road line Lv extracted from the V-disparity map, a sub-U-disparity map with the road; wherein a sub-U-disparity map relates to a part of the U-disparity map relating to the road; obtaining, from the V-disparity map, points below the extracted road line Lv with a distance from a camera for picking up the disparity map that is less than a predetermined distance threshold; extracting, from the disparity map, points that correspond to the points obtained from the V-disparity map; projecting the points extracted from the disparity map onto the sub-U-disparity map as reliable road points; extracting, from line segments obtained by a straight line fitting based on the reliable road points, road edge line segments that satisfy a predetermined road edge condition from the sub-U-disparity map, wherein the predetermined road edge condition includes the following: the sum of the absolute value of a horizontal and vertical intercepts of such a line segment, is the minimum value from all of the line segments; and the real length corresponding to the line segment in a real-three-dimensional world coordinate system is greater than a predetermined length threshold; wherein the horizontal intercept is the intersection between a straight line corresponding to such a line segment and the horizontal axis; and the vertical intercept is the intersection between a straight line corresponding to such a line segment and the vertical axis; extracting the road edge from the sub-U-disparity map, by; calculating an end point of an extracted road edge line segment when a road edge line segment is extracted, determining a region of interest for extracting the next road edge line segment by setting an angle change range based on the angle of the extracted road edge line segment and a region in an angle change range, and extracting the next road edge line segment with a start point that is the calculated end point from the region of interest; and repeating the process of extracting the road edge line segment, until no road edge line segment can be extracted.