Thin film type flow guide device of liquid cargo tank, pressure alarm system and liquefied gas ship

The invention discloses a liquid cargo tank film type flow guide device, a pressure alarm system and a liquefied gas ship in the technical field of liquid cargo tank leakage liquid cargo treatment. The liquid cargo tank film type flow guide device comprises a bent pipe part, a flow guide part and a straight pipe part which are sequentially connected, and a flow guide cavity is formed in the flow guide part; an upper supporting protruding part and a lower supporting protruding part are arranged in the flow guide cavity, and the upper supporting protruding part is connected with an elastic piece barb in the rear cavity. The sealing film is arranged between the flow guide part and the straight pipe part; and the spring and the thrust ball are respectively arranged in the rear chamber and the front chamber and are connected through the connecting rope. Leaked liquid goods in the leakage channel are guided through the bent pipe part, the flow guide part and the straight pipe part, the leakage channel is sealed thr