The invention discloses a dual-fuel air supply system of an ultra-large container ship and the ultra-large container ship. The dual-fuel air supply system of the ultra-large container ship comprises an LNG (Liquefied Natural Gas) bunker, a cabin and a gas processing room, wherein the LNG bunker is arranged below a deck, the cabin is arranged below the deck and is located on the tail of the ship, the gas processing room is arranged above the deck, and fuel in the LNG bunker is conveyed to the gas processing room to be processed and is conveyed to gas equipment in the cabin. According to the dual-fuel air supply system of the ultra-large container ship, the LNG bunker is arranged below the deck, and the arrangement of the LNG bunker comprehensively considers the influence of the LNG bunker on the stability of the ship, the partition of fire separation and hazardous areas and the convenience in arrangement of a natural gas pipeline. Additionally, the inner space of the ultra-large container ship is used to the maximum, the maximum effective volume can meet the requirement that LNG fuel can be used by the ultra-large container ship on the entire route, and at least the requirement thatthe ship sails in a round trip on a set route can be met.