Abstract: The synthesis process of geranyl nitrile from citral by catalytic ammoxidation was optimized. The factors affecting the conversion rate of citral and the yield of geranyl nitrile, including ammonia(NH₃H₂O) dosage, hydrogen peroxide(H₂O₂) dosage, reaction time, reaction temperature, the type and dosage of catalyst, and solvent type were investigated. Through univariate and onthogonal experiments, the optimal synthesis conditions for geranyl nitrile was citral 35 mmol, n(citral):n(NH₃·H₂O):n(H₂O₂):n(CuCl)=1:2.7:5.5:0.045, H₂O₂ as oxidant, CuCl as catalyst, 36 mL isopropanol as solvent, and the reaction time of 5 h, the reaction temperature of 10-15 ℃. At these synthesis conditions, the conversion ratio of citral was 97.50% and the yield of geranyl nitrile was 94.59%. When the conditions were amplified by 2, 3 and 5 times, the conversion rates of citral were 95.75%, 95.05% and 95.00%, and the yields of geranyl nitrile were 92.88%, 92.20% and 92.15%, respectively.