Grader is the main machinery used for shaping and leveling in earthwork, which is widely used in large-scale ground leveling operations such as roads and airports. The reason why the grader has extensive auxiliary operation ability is that its scraper can complete 6-degree motion in space. They can be carried out individually or in combination. Grader can provide sufficient strength and stability for subgrade construction. Its main methods in subgrade construction include leveling operation, slope brushing operation and embankment filling.

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.