Vacuum thermos and thermos work the same way, but the structure between the two is very different. The inner tank of the thermos bottle is essentially a small bottle in a large bottle. The mouths of the two bottles are sealed to form a cavity. The diameter difference between the two bottles is about one centimeter, so the cavity volume of the inner tank is large, and the cavity is vacuumed. Afterwards, due to the action of atmospheric pressure, the inner and outer bulbs of the gallbladder are compressed. When the gallbladder breaks, a large amount of air is instantly filled into the cavity, and the airflow impact causes the glass bulb to burst and sound. The vacuum glass of the vacuum flask has a gap of only 0.1 to 0.2 mm, and the volume of the vacuum glass cavity of two square meters is only as large as a table tennis. Even if the vacuum glass of the vacuum flask is broken, the air charge amount is small, airflow impact will not be formed, and even if cracks appear on the glass plate surface, bursting and loud noise will not occur.