Black hole illusion (BHI) refers to when landing on water, in dark areas, and areas lacking surface features due to snowfall, this lack of surface features can produce an illusion that the aircraft is flying at a higher altitude than the actual situation. Pilots who do not perceive this illusion will have a lower approach altitude. It reflects the pilot's wrong perception of altitude and distance under special conditions, which will bring psychological pressure to the pilot, and this illusion often leads to air crashes.