Indonesia has the opportunity to become a country with a very high level of risk of water shortages. This means that water reserves are no longer sufficient to meet demand. The desalination method is needed to solve the problem of the water crisis in Indonesia. In this study, a new alternative desalination method with droplet atomization was developed that utilizes the phenomenon of air entrainment. This study analyzes the effect of nozzle diameter on the spray angle to characterize the mist in the desalination process from the design results. The research was conducted by observing the spray angle using a video camera image processing program. It was found that the nozzle diameter affected increasing the nozzle spray angle with increasing pressure. The 0.5 diameter nozzle has a wider spray angle than the others, with the highest angle of 62,250 at a pressure of 9 bar.