Ionic liquid electrospray thrusters are easy to miniaturize， and have the characteristics of high specific impulse and precise thrust accuracy. They are suitable for small satellites， space gravitational wave detection， etc.， and possess great potential for development. The understanding and study on the working mechanism of electrospray not only are supportive of the engineering applications of ionic liquid electrospray thrusters， but also lay a foundation for their further development in the future. Therefore， in this paper， the research progress of the working mechanism of ionic liquid electrospray thrusters is overviewed. First， the development history and current situation of electrospray thrusters are reviewed. Then， taking the three basic working processes of ionic liquid electrospray thrusters as the starting point， the basic theories and research status of the cone jet formation and emission mechanism， the beam modes and extraction characteristics， and the plume neutralization mechanism are introduced and summarized. Finally， prospects are proposed for ionic liquid electrospray thrusters on the future research direction of their working mechanism and the development directions of their engineering applications.