Simulation　of　frost　formation　process　on　cold　surface　is　carried　out　based　on　fractal　theory　combined　with　phase　change　dynamics.　Before　frosting,　the　phenomena　of　vapor　condensation,　droplet　growth　and　frozen　on　cold　plate　are　successfully　simulated　based　on　phase　change　dynamics　and　then　a　fractal　simulation　of　the　frost　formation　and　growth　process　over　the　frozen　droplets　is　carried　out　based　on　diffusion　limited　aggregation　(DLA)　model.　The　simulation　results　accord　well　with　the　experimental　results.　The　time　when　the　condensation　droplets　are　present　and　frozen　on　the　surface　during　simulation　process　is　nearly　the　same　as　the　experimental　result.　Before　the　droplets　are　frozen,　the　trend　that　the　surface　contact　radius　of　the　droplet　varies　with　condensation　time　is　similar　to　actual　one.　The　simulation　results　also　show　that　the　thickness,　of　frost　layer　is　nearly　equal　to　the　measured　value.　By　that　means,　the　feasibility　of　this　method　of　simulating　the　frost　formation　is　verified　and　the　new　attempt　made　to　foster　the　combination　between　fractal　theory　and　phase　change　dynamics　is　of　great　significance.　This　study　also　provids　a　foundational　theory　work　for　a　more　reasonable　and　accurate　frosting　process　model.