The invention relates to an ionization device of a vacuum UV lamp, comprising an ionization chamber, a UV lamp, a repulsion plate, a focusing ring, a small hole plate, a capillary sampling system and a lens system. The design of the focusing ring can increase about 2 orders of magnitude of signal strength. An ionization source in the ionization device has two working modes, namely a UV light ionization mode and a UV light and electron impact ionization mode, and the two modes can be converted by voltage regulation. The ionization device of the vacuum UV lamp has the characteristics of wide of range of sample to be detected, high sensitivity, low power consumption, long life, wide range of working air pressure, and the like, and has wide application prospects in process monitoring and real-time online analysis of organic pollutants.