The evaporation treatment of high-level liquid waste is a key step in the reprocessing of spent fuel. Droplets generated by the bursting of bubbles in the steam generator may carry particles from the liquid to the air, leading to blockage of the evaporation outlet. In order to investigate the causes of blockage, it is necessary to determine the entrainment characteristics of the droplets. A high-speed camera is used to investigate the behavior of droplets generated by the burst of bubbles on the free surface, parameters of bubbles and droplets are obtained by image processing technology. The single bubble burst behavior can be divided into the drainage stage before the bubble bursts, the bubble burst stage, and the film droplet generation stage according to time. The models for each stage have been explored. The results indicate that the film thickness decreases exponentially by 2/3 with the bubble lifetime in different liquid solutes. Bubble lifetime obeys a Weibull distribution with a shape parameter of 4/3. The bubble lifetime significantly affects the bubble film drainage process and thus has a significant impact on the diameter and number of film droplets. The model for the diameter distribution of film droplets is calculated based on the gamma distribution followed by normalized droplet diameter and the corresponding relationship between film droplet diameter and bubble lifetime. By combining the concept of critical droplet diameter based on Stokes’ law of droplet motion. The droplet entrainment factor can also be calculated. Droplets are unlikely to be entrained in the gas space under bubbly flow conditions. The particles carried into the air are highly likely to be turbulent entrainment effects based on the actual two-phase flow conditions of the evaporator liquid level.