In order to study the interaction between composite photocatalytic material TiOsub.2@LDO and matrix asphalt, the four-component 12 molecular structure model of 70# matrix asphalt was optimized by using software Materials Studio 2020, and its heterostructure with TiOsub.2@LDO composite was modeled. The bonding performance between asphalt and composite photocatalytic material was analyzed by interface energization, and the diffusion performance between asphalt and composite photocatalytic material was analyzed from the perspectives of particle movement and Z-direction density. By changing the temperature and other parameters in the simulation process, the change in bonding strength between TiOsub.2@LDO and asphalt was investigated. Through the calculation and analysis of interaction energy, it was found that the adsorption and bonding strength between asphalt and TiOsub.2@LDO were the strongest at 40 °C. At the same time, the diffusion performance was studied, and it was found that the molecular diffusion distribution of TiOsub.2@LDO was more extensive at 60 °C, which laid the foundation for further blending of asphalt and TiOsub.2@LDO. The simulation results show that TiOsub.2@LDO molecules have a certain attraction to asphalt molecules and can modify the matrix asphalt to some extent.