A model to solve the electrostatic field of multiple needle electrodes spraying blade was established. The distribution regularities of electric potential and electric intensity in the space out of multiple needle electrodes spraying blade were analyzed by Ansoft Maxwell software, and the influence of different gap of needle electrodes on electrostatic field was researched. Meanwhile, the particle sizes of the droplets atomized by the spraying blade with different gap needle electrodes were measured by laser particle size analyzer and the distribution law of the droplets was analyzed by computer. The results indicated that the highest electric intensity near the needles could be promoted to 2.7×106V/m by the multiple needle electrodes, and the amplitude variation of electric field near the needle electrodes was the maximum. A region with high electric intensity uniform distributed could be formed when the gaps of needle electrodes were 2mm which was the optimal gap, and the particle size of droplets atomized by the spraying blade decreased to 42μm. Furthermore, the distribution of particle size was more uniform, and the results of experimental were consistent with the characteristics of electrostatic field obtained by evaluation．