Abstract: Vacuum pipelines are often used in LNG stations to reduce the LNG loss because of the low temperature of LNG(Liquefied Natural Gas).The vacuum degree of the vacuum pipeline is an important factor in ensuring the insulation of the pipeline.Once the LNG pipeline leaks and the vacuum is lost, the insulation performance of the pipeline will be reduced, and the large amount of gasification of LNG will cause safety hazards such as fires and explosions.Traditional judgments often use empirical observations or on-site data and formula calculations to make judgments on LNG pipeline leakage, which has limitations.This paper uses FLUENT numerical simulation software to transform LNG pipeline into a mathematical model, simulates the temperature field of LNG pipeline leakage, analyzes the pipeline heat distribution after the loss of vacuum, studies the heat change law after pipeline leakage, and identifies key dangerous parts of the pipeline.Being able to discover problems scientifically has important practical significance for accident prevention and control, and at the same time provides a theoretical basis for the scientific management of LNG stations.