In this study, the compatibility of phase change material(PCM) in asphalt was investigated using several methods. Initially, solubility parameters, radial distribution functions, and relative concentrations of PCM modified asphalt were examined through molecular simulations to explore its compatibility. Subsequently, the phase structures of different PCM modified asphalt were analyzed using fluorescence microscopy experiments on both upper and lower samples. Finally, the compatibility differences among PCM modified asphalt samples with varying naphthenic oil contents were evaluated through softening point and Brookfield viscosity tests. The results indicate that higher naphthenic oil content in encapsulated PCM leads to closer solubility parameter alignment with the base asphalt. At a naphthenic oil content of 50% in encapsulated PCM, significant interactions occur between PCM and asphalt components. The concentration distribution curve of PCM molecules in the asphalt approaches 1.0, indicating excellent compatibility between encapsulated PCM and asphalt. Overall, the results from fluorescence microscopy and conventional tests are consistent with simulation outcomes. The only discrepancy observed is that conventional experimental results for the PCM-60% sample slightly outperform those for the PCM-50% sample. •A means of enhancing the compatibility of encapsulated PCM with asphalt was proposed.•Novel molecular structure of oil-containing phase change material was established.•A multi-scale study on the compatibility of PCM modified asphalt was conducted.•The optimal content of naphthenic oil in encapsulated EG/PEG was confirmed.