Ice　thermal　storage　device　using　micro　heat　pipe　arrays　and　closed　rectangular　fins　has　been　proven　to　exhibit　excellent　thermal　performance.　However,　neither　the　details　of　ice　formation　inside　the　device　nor　the　dominant　factors　affecting　the　performance　of　the　device　and　the　optimal　fin　geometric　parameters,　have　been　reported.　In　this　study,　numerical　simulations　were　performed　to　investigate　the　ice　packing　factor,　dynamic　ice　front　evolution,　and　effects　of　fin　geometric　parameters　including　fin　height,　thickness,　and　spacing　on　the　thermal　performance　of　the　proposed　device.　Results　demonstrated　that　the　fins　effectively　improved　ice　formation　homogeneity　and　accelerated　ice　formation.　The　decreased　fin　height　and　spacing,　increased　fin　thickness　were　positive　to　enhance　thermal　characteristics.　Taguchi　method　was　used　to　obtain　the　contribution　ratio　of　independent　fin　parameter　and　optimal　geometric　fin　configuration　to　the　thermal　performance.　Fin　thickness　played　a　dominant　role　with　a　contribution　rate　of　up　to　44.52%,　followed　by　28.65%　for　fin　height　and　26.83%　for　fin　spacing.　From　the　perspective　of　trade-off　between　ice　formation　rate　and　manufacturing　cost,　the　optimal　height,　spacing,　and　thickness　of　the　fin　structure　for　practical　engineering　application　were　determined　to　be　15,　10.1,　and　0.25　mm,　respectively.