Abstract: In order to explore the recycling feasibility of municipal solid waste incinerator fly ash applied in asphalt pavement, on one hand, the basic physical properties of fly ash were studied by the pavement fillers experiment method. On the other hand, the chemical properties of fly ash, such as the specific surface area of BET, pore diameter, pore volume, apparent morphology, chemical composition and thermal property were characterized by specific surface area and pore size analyzer, scanning electron microscope (SEM), X-ray fluorescence spectrometer (XRF), X-ray powder diffractometer (XRD) and simultaneous thermal analyzer (STA). Results show that particle size distribution of fly ash is similar to mineral powder, and it exhibited smaller density, bigger coefficient of hydrophilic, bigger moisture content, stronger alkalinity, higher loss of ignition, poorer dimensional stability, higher content of soluble salt and bigger specific surface area of BET, larger pore diameter and larger pore volume by comparing with mineral powder. Furthermore, fly ash has porous surface, complex mineral phase, high activity and active thermal property. However, it has good thermal stability and small thermal weightlessness in the construction of asphalt mixture temperature range. In view of the physical and chemical properties of fly ash, it can be known that the water stability and strength of asphalt pavement is influenced by the soluble salt of fly ash, and the high temperature stability and low-temperature anti-cracking performance of asphalt pavement is influenced by surface pores, high surface energy, strong alkalinity and high moisture content of fly ash. The corresponding theoretical improvement measures are suggested.