Abstract: Process of liquid film fragmentation and droplet formation in a two fluid atomizer was explored, and two fluid atomizer nozzles with different pitches and nozzle outlet shapes were conducted simulation research．The process of liquid film formation and fragmentation in a two fluid atomizer was simulated and analyzed．By coupling VOF-DPM model, droplet size distribution during atomization process was successfully obtained, and accuracy of simulation results was verified through experiments．Research results indicated that pitch in a two fluid atomizer had a significant impact on velocity of gas phase, and when high-speed gas phase flowed out of the outlet, it formed a large turbulence to lift liquid phase near guide pipe．Different nozzle structures could result in different lengths of liquid phase extension and different completion times for primary crushing．The higher the gas phase velocity, the smaller the droplet size produced by secondary crushing．For nozzles with lower gas phase velocity, secondary crushing was completed in form of liquid mass, while for nozzles with higher gas phase velocity, secondary crushing was completed in form of liquid belt．