In order to explore the practical application of industrial papermaking waste in road engineering, based on dynamic shear rheological experiments, the adhesion of lignin-modified asphalt at the micro-interface under the conditions of light and heat coupling was studied. A high-resolution optical microscope was used from a macro perspective. The compatibility of the apparent interface of the asphalt mortar system is analyzed. The results show that the interface behavior of the lignin-modified asphalt mortar system reflects the consolidation ability of the overall asphalt material to a certain extent, based on the relationship between the Ashida.M-α and Ziegel.K-β values with the change of the powder-to-rubber ratio and temperature. Both of them showed a trend of first rising and then falling with the increase of lignin content, which means that the modified asphalt with high powder-to-binder ratio exhibits good anti-aging performance, but it brings weak interfacial bonding performance. . Modified asphalt with high powder-to-binder ratio is prone to interface phase separation and destruction under the conditions of light-heat coupling. In the medium and high temperature range, the cohesive force of asphalt mixture is greatly affected by temperature changes. From the Cole-cole diagram, it can be seen that the compatibility of each asphalt mortar system is good, and it exhibits strong viscoelasticity and resistance to deformation at high temperatures.