In　this　work,　the　deterioration　mechanism　of　organic　snowmelt　salt　on　asphalt　mastic　in　salt　storage　asphalt　pavements　was　systematically　investigated.　The　example　of　sodium　formate　snowmelt　salt,　the　molecular　models　of　asphalt　mastic　containing　sodium　formate　snowmelt　salt　and　its　interface　were　established　based　on　the　experiments　conducted　on　asphalt　mastic.　The　impact　of　sodium　formate　on　the　thermodynamic　properties　and　healing　behaviour　of　asphalt　mastic　were　studied　from　the　microscopic　perspective.　The　results　showed　that:　(1)　The　addition　of　sodium　formate　snowmelt　salt　made　the　asphalt　mastic　viscous　and　hard,　and　while　reduced　the　self-healing　properties.　(2)　The　asphalt　mastic　model,　which　was　examined　for　density,　solubility　and　free　volume　fraction,　was　able　to　clearly　represent　its　thermodynamic　properties.　(3)　The　increase　in　the　viscosity　and　modulus　of　the　asphalt　mastic　containing　salt　could　be　possibly　attributed　to　the　reduction　in　the　molecular　diffusion　rate　and　the　increase　in　the　aggregation　level.　(4)　Since　the　hydrogen　bonding,　the　sodium　formate　would　form　larger　aggregates　with　the　mineral　powder,　which　could　induce　the　decrease　in　the　ductility.　(5)　Sodium　formate　also　can　lead　to　the　asphaltene　form　a　weak　area　of　distribution　near　the　interface　and　reduce　the　self-healing　properties　of　the　asphalt　mastic.　This　research　provides　valuable　insights　for　the　analysis　of　the　deterioration　of　asphalt　pavements　by　snowmelt　salts.