Abstract: Zinc nitride (Zn3N2) is a promising nitride semiconductor due to its special electrical and properties. Currently, Zn3N2 thin film products prepared by various thin film technologies have been widely used in light emitting diodes, sensors, thin film transistors and other fields. However, the methods available for preparing Zn3N2 powder were very limited. In this work, powder Zn3N2 was synthesized with a simple method of directly nitriding zinc powder with ammonia. It was found that, just by introducing glycerol as an additive, the purity of the prepared Zn3N2 powder could be increased by 52.17%. In addition, the dispersibility of the product is also greatly improved. These results indicate the important role of glycerol additive in the formation of Zn3N2 product. When the ratio of glycerol to zinc powder was 0.20 (mL/g), the purity of the product can reach to about 96%, optical band gap is 2.60 eV. Finally, the critical role of glycerol in the synthesis of Zn3N2 was analyzed.