Due to the large number, large size and wide distribution of billboards built-in airport terminals, they easily become ignition sources and fuses that promote the spread of fires after the fire, and such fire hazards are often ignored. To study the spread of airport terminal fires caused by billboards, the combustion test of 12 common billboard materials Polyethylene Glycol Terephthalate (PET) and Polyvinyl Chloride (PVC) was carried out by monomer combustion experiment. Then, the experimental data were substituted into the FDS simulation software to simulate and verify the fire in the airport terminal, and the fire development, smoke diffusion, visibility change, CO generation and temperature change were studied. The results show that the scope of fire spread to the airport terminal after the burning of advertising materials is spatially limited, which is related to the location and height of the fire source of the billboard. The large amount of smoke the fire generates forms an inverted cone plume shape, and the phenomenon of roof jet and smoke settlement will occur. The temperature of the smoke that spreads to the ceiling reaches 300°C, reaching 3/8 of the area on the second floor of the terminal at 700s. The smoke hazard of the floor above the ignition point is much greater than that below the ignition point, and the horizontal spread rate of smoke above the ignition point accelerates with the increase of floor height. Visibility analysis showed that visibility near the roof and near the fire source was low, and the visibility level had little impact on the escape of personnel. As the fire develops, the farther away from the fire source, the faster the CO volume fraction of the floor reaches the critical value. This study provides a theoretical basis and data support for the fire safety assessment of the multi-functional public area of the terminal