Abstract
Since the electrospray phenomenon was discovered, there is still a debate about how the matter is charged in the soft ionization phenomenon represented by ESI. Scientists have described this process from different perspectives, but current theories still cannot correctly explain many experimental phenomena. At the same time, the immaturity of the theory restricts the application of soft ionization techniques, obviously, the slow development of the theory restricts the design and development of ion source, making the ion source encounter many bottlenecks from the laboratory to the commercialization. In this paper, the principle of electrospray ion source is briefly introduced, and the application of ion transport mechanism is discussed and prospected.