Vacuum ultraviolet photo ionization(VUV-PI) is a universal soft ionization source for mass spectrometry(MS).The VUV-PI-MS is quite suitable for on line rapid analysis as its mass spectrum is free of fragment ion interference,easy to be interpreted and high sensitive.According to different analytes,VUV-PI could be used in single photon ionization mode or chemical ionization mode achieved by dopant,which could be used for gas,liquid and solid sample analysis,as well as for imaging analysis.The ionization principle of the VUV-PI and the current type of vacuum ultraviolet light source are firstly introduced in this article,then the factors affecting the sensitivity of photo ionization MS and its technical improvement measures are analyzed,and finally,the applications of VUV-PI-MS technology in environmental analysis,chemical products on line analysis,national safety analysis and related application research in biomedical analysis are also presented.In the conclusion,the advantages and disadvantages of VUV-PI are summarized,and the perspectives on developments of performance and applications of VUV-PI technique are looked forward to.