By electrostatic spraying, ethyl cellulose (EC) was dissolved in dichloromethane (DCM) to prepare EC microparticles, and the effects of EC mass concentration, injection speed, voltage and receiving distance on the morphology and diameter of microparticles were studied. The morphology of EC particles was observed through scanning electron microscope, and the particle size rules were analyzed. The results showed that when the EC concentration was 2.5 %, the injection speed was 1.5 ml/h, the voltage was 17.5 kV, and the receiving distance was 15cm, disc-shaped EC particles were in good morphology with average particle size of 7.68μm and even dispersion could be obtained. Too low or too high EC mass concentration and too low or too high injection speed increased the irregularity of the particles. Increasing the voltage reduced the particle size of EC particles, and the particle size increased with the increase of the receiving distance.