The invention relates to a mobile robot mechanism, in particular to a routing inspection robot mechanism applicable to a narrow routing inspection working space. The routing inspection robot mechanism comprises a front box body, a rear box body, first guide rails, a front arm and a rear arm, wherein the structure of the front arm and the structure of the rear arm are the same. The front arm and the rear arm are respectively provided with a traveling mechanism and a clamping mechanism, and each traveling mechanism and the corresponding clamping mechanism are placed above an overhead ground wire and below the overhead ground wire respectively. The number of the first guide rails is at least two, all the first guide rails are parallel to one another, the rotatable front box body and the rear box body are arranged at the two ends of each first guide rail respectively, and the front arm and the rear arm are mounted on two outermost side first guide rails respectively. The front arm and the rear arm respectively have three degrees of freedom, namely moving along the first guide rails, lifting in the vertical direction and rotating in the vertical direction. According to the routing inspection robot mechanism applicable to the narrow routing inspection working space, a wheel-arm combined mechanism is adopted, the characteristic of a wheel type mechanism and the characteristic of an arm type mechanism are combined, the function of traveling along the line is achieved, and the function of stepping over obstacles is also achieved.