Floating　photovoltaics　(PVs)　are　progressively　constructed　in　the　ocean　sea;　therefore,　the　effect　that　freak　waves　have　on　their　structural　design　needs　to　be　considered.　This　paper　developed　a　dedicated　numerical　model　coupling　the　floating　PV　platform　and　mooring　line　structures　to　investigate　their　dynamic　responses　under　freak　waves.　A　feasible　superposition　approach　is　presented　to　generate　freak　wave　sequences　via　the　combination　of　transient　waves　and　random　waves.　A　large　floating　PV　platform　moored　by　twenty　lines　for　a　water　depth　of　45　m　was　designed　in　detail　according　to　the　actually　measured　ocean　environmental　and　geological　conditions.　The　global　time　domain　analyses　of　the　floating　PV　mooring　structures　were　implemented　to　obtain　dynamic　responses,　including　PV　platform　motions　and　the　mooring　line　configuration　and　tension　under　freak　waves.　A　comparison　of　the　response　results　with　those　caused　by　random　waves　was　conducted　to　illustrate　the　intuitive　evidence　of　the　freak　wave　effects,　which　offer　a　significant　reference　for　the　preliminary　design　of　the　floating　PV　platform　and　mooring　line　structures.