Portable rail bottom scanning method

The invention relates to a portable rail bottom scanning method, which comprises the following steps of: driving a single transmitting probe and a single receiving probe to reversely move along the length direction of a steel rail under the condition that the single transmitting probe and the single receiving probe are respectively clung to two side surfaces of the rail bottom so as to realize comprehensive detection of the transverse width of the rail bottom; meanwhile, the single receiving probes which are tightly attached to the top face of the rail bottom and form different deflection angles with the length direction of the steel rail are used for scanning and detecting the edge of the rail bottom foot, the rail bottom angle and the combination area of the rail bottom and the rail waist, scanning of different areas of the rail bottom welding seam is achieved, and therefore the purpose of more conveniently conducting all-dimensional scanning on the welding seam rail bottom is achieved; and different types