Molecular　simulations　have　been　successfully　applied　for　studying　the　kinetic　properties　of　supercritical　fluids,　extremely　in　exploring　the　microscopic　mechanisms　of　high-pressure　and　high-temperature　fluids.　Molecular　simulation　is　an　efficient　and　convenient　way　to　investigate　complex　molecular　systems　with　supercritical　water.　Polycyclic　aromatic　hydrocarbons　(PAHs)　are　typical　coal　chemical　pollutants.　Molecular　simulations　using　PAH　model　compounds　were　carried　out　to　explore　the　effects　of　supercritical　water　on　solvation　free　energies　and　structural　properties.　The　water　density　was　ranging　from　0.1　g/cm3　to　0.3　g/cm3　and　temperature　was　increased　from　380　°C　to　440　°C.　In　terms　of　PAHs　in　this　study,　the　simulations　and　calculations　revealed　that　the　solvation　free　energy　remained　negative　and　simultaneously　varied　with　water　density　and　temperature.　This　work　is　expected　to　provide　a　theoretical　support　for　understanding　the　dynamic,　structural　properties　and　the　solvation　properties　of　different　aromatic　hydrocarbons　in　supercritical　water　environment.　©　2020