Grader is a kind of high-speed, high-efficiency, high-precision and multi-purpose earth-moving machinery. It can complete large-scale ground leveling, ditching, slope scraping, earth pushing, snow removal, soil loosening, compaction, cloth distribution, mixing, loading assistance and land reclamation for roads and farmland. It is an important equipment in national defense engineering, mine construction, road construction, water conservancy construction and farmland improvement. Highway subgrade is the foundation of pavement and an important part of highway engineering. Subgrade bears the traffic load from the pavement and is the supporting structure of the pavement. It must have sufficient strength, stability and durability. According to the different topography, embankment and cutting are generally used for highway subgrade.