Abstract：Based on the DPM model, droplet breakage model, as well as the heat and mass transfer model between droplets and gas, the simulation of droplet atomization flash in flash chamber was carried out. Different parameters were studied to analyze the non-equilibrium fraction (NEF), the non-equilibrium temperature difference (NETD) and flash efficiency. The results showed that as the initial temperature of the droplet increased, the NEF and NETD of the droplet decreased, while the flashing efficiency showed opposite changing trend. The NEF and NETD of the droplets decreased first and then increased as the pressure of the flashing environment increased, but the flashing efficiency decreased as the flash pressure increased. The NEF and NETD of the droplet increased as the nozzle aperture increased, while the changing trend of flash efficiency was reversed. The initial temperature of the liquid was 150 ℃, the ambient flash pressure was 60 kPa, and the nozzle diameter was 3 mm, which was the optimal parameter.