The droplets velocity in spraying fan of flat fan nozzle LU120—03 was tested by phase Doppler particle analyzer (PDPA). The initial velocity was liquid-sheet velocity and the velocity distribution in spraying fan was confirmed. The results showed that the velocity of minimum droplets in spraying fan edge was lower than that in central position near the nozzle, so it was more likely to drift; the fine droplets velocity decreased rapidly far away from the nozzle so that the droplets were very easy to result in drift influenced by airflow. 