The metastable zone width of ammonium bicarbonate is an important factor affecting its crystallization process. To further analyze its specific regulation mechanism, this paper uses dynamic method to explore the influence mechanism of key parameters such as temperature, magnetic field, stirring rate and solvent titration rate on the metastable zone of ammonium bicarbonate and optimize the operation conditions. The results showed that with the increase of temperature, Molar fraction of ethanol increased, the nuclear energy barrier of ammonium bicarbonate decreased, and the width of metastable zone became narrower. At the same temperature, under the condition of magnetic field, the super solubility curve showed a downward trend and the metastable zone narrowed, but the trend weakened with the increase of Molar fraction of ethanol. When the stirring rate increased from 200 r/min to 600 r/min, the metastable zone width decreased first and then increased. The width of metastable zone increased with the increase of the droplet acceleration rate of solvent. When the droplet acceleration rate increased to 8 mL/min, the change of metastable zone tended to be flat. Increasing the temperature, increasing the magnetic field, increasing the stirring rate within a certain range, and taking the appropriate drop acceleration rate can promote the crystallization process.