The requirements of large-scale road maintenance machinery for escorts without power return are: when the self-return stops, it must be hung at the rear of the freight train. When returning, the driver of the large-scale road maintenance machinery must be escorted, responsible for the technical inspection of the vehicle and contact the train driver to explain the technical requirements such as mitigation. Large-scale maintenance machinery is a mechanical, hydraulic, electrical and pneumatic machine, which adopts a lot of advanced technologies, such as electro-hydraulic servo control technology, automatic detection technology, microcomputer control technology and laser collimation technology. Large-scale maintenance machinery mainly refers to the machinery and equipment for the maintenance, repair and renovation of railway lines, including equipment such as track ballast cleaning, track ballast tamping and compaction, track ballast vibration stability and track ballast shaping.