The accident occurred around 11.30am at Dittingen, the Swiss newspaper Tages-Anzeiger said on its website.
Just before the crash three C42B-type planes, part of a German group called the "Grasshoppers", were flying when two of them collided for reasons that remain unknown, a police statement said.
The 50-year-old pilot of one of the planes died in the accident after his plane crashed into a barn.
The pilot of the other plane was able to escape by parachute and was uninjured. His plane crashed on the outskirts of the village.
No one was injured on the ground.
An investigation has been opened into the reasons for the crash.
The air show in Dittingen has been in existence for over 60 years and draws hundreds of pilots from Switzerland and abroad, organizers said.
In 2005 a fatal accident occurred at the same show, according to the Swiss news agency ATS.