The present invention relates to an ozone generator and applications of the ozone generator in ion mobility spectrometry and mass spectrometry detection. The ozone generator mainly comprises an ultraviolet light source and an ozone reaction chamber, wherein the front end of the ozone reaction chamber is provided with an air inlet, and the rear end is provided with an ozone removing port. According to the present invention, the ozone generator has characteristics of simple structure and small volume, and the generated trace ozone can be used for reaction reagent ion modification and reduction-state compound front end oxidation in the ion mobility spectrometry or mass spectrometry detection.