Abstract: In order to study the characteristics of laser-induced droplet plasma, based on the synchronous system of pulsed laser and droplet, the direct imaging method and the shadow method were used to study the expansion characteristics of droplet plasma and the motion of droplets. Firstly, the evolution of the plume of water droplet plasma over time was studied by using the intensified charge-coupled device (ICCD) direct imaging method. Then, the shadow image evolution of laser water droplets was studied by shadow method. The changes of the shock wave and the droplet clusters generated by the laser droplets were observed, the expansion speed and the expansion distance of the shock wave with time were calculated and analyzed. The results show that the plasma expansion shape of droplets induced by laser is approximately elliptical, with one side along the incident direction of the laser having a higher radiation intensity. The expansion of the plasma within 100ns is approximately linear expansion, and the expansion tends to be stable after 100ns. In addition, the shock wave expansion radius increases linearly with time and the shock wave expands at a rate of approximately 90m/s. These findings can provide a reference for laser-induced droplet experiments.