According to the technical grade standard, it is divided into four grades: advanced, sub-advanced, intermediate and low. According to mechanical properties, it can be divided into rigid pavement (mainly cement concrete pavement) and flexible pavement (asphalt pavement). Rigid pavement is characterized by high strength, good skid resistance, long service life and full use of ground materials. Flexible pavement is characterized by comfortable driving, good smoothness, no transverse joints, low noise, less dust, no maintenance period, and convenient mechanized construction and maintenance.