Cellulose fiber（CF） and glass fiber（GF） have been selected for asphalt concrete reinforcement to cope with the drawbacks of insufficient enhancement in comprehensive properties. Furthermore， the mechanism of fiber composite modification was explored by determining the pavement performance of asphalt concrete with varying proportions of CF/GF. The results indicate that the composite modification process of CF/GF improves high-temperature property， low-temperature performance and water stability of asphalt concrete effectively. As the mass ratio of CF/GF is 1∶3 in asphalt concrete， the dynamic stability is 2.2 times that of the CF modified asphalt concrete. The maximum flexural-tensile strain is 13.3% higher than that of the CF modified asphalt concrete when the specimens are subjected to low-temperature damage. This enhancement can be attributed to the functional aspects which is originated from the adsorption， reinforcement， and crack retarding of composite fibers in the matrix of asphalt concrete， thus the durability is improved under the coupling effects of temperature changes， moisture damage， and stress loading.