In　this　paper,　the　Fuel　Rod　Melting　Progression　Apparatus　used　for　the　visualization　of　severe　accident　phenomena　has　been　established　to　study　the　complex　phenomena　of　fuel　rod　melting,　melt　expansion　and　dissolution　of　typical　Pressurized　Water　Reactorstructures.　And　a　series　of　experiments　have　been　carried　out.　The　experiment　carried　out　a　visualizing　study　using　zinc-aluminum　and　zirconium-alumina　structure　fuel　rods.　The　transient　axial　temperature　distribution　of　the　fuel　rod　cladding　and　the　dynamic　process　of　melt　expansion,　migration　and　relocation　during　a　severe　accident　have　been　obtained.　Based　on　experimental　data,　this　research　has　conducted　an　in-depth　analysis　of　the　physical　phenomena　and　process　related　to　the　flow,　expansion,　solidification　and　migration　of　the　melt.　And　the　research　provides　experimental　data　support　for　the　development　of　models　analyzing　severe　accidents.　©　2022　Elsevier　Ltd