Introduces the aging process of asphalt, mechanism of waste asphalt recycling agent can be divided into three categories: solubilization dispersion mechanism, diluted reconcile mechanism and wax crystal dispersion mechanism. Asphalt recycling agent should have three levels of functionality, asphalt coordination structure, restore road performance, durability and weather resistance. Regenerated catalyst not only to meet the asphalt coordination structure, restore road performance requirements, but also to ensure that the construction process safety, environmental protection and regeneration of the weather and other aspects of the road.