The ZnFe2O4/ZnO catalyst was prepared by an improved amorphous citric precursor method, and was applied in the cyclodehydration of diamine and 2,3- butanediol to synthesize alkylpyrazines.The catalyst was characterized by means of XRD and FT-IR. The effects of Zn/Fe molar ratio, reaction temperature, carrier gas space velocity on the conversion of 2,3-butanediol and selectivity of alkylpyrazines were studied in detail. The results indicate that the optimum conditions for the synthesis of alkylpyrazines were n(Zn):n(Fe)=2:1, reaction temperature 380℃, material flow rate 0.02mol/min, carrier gas space velocity 1440 h-1. The conversion of 2,3-butanediol was 93.38% and the selectivity of alkylpyrazines was 85.47% . The yield of 2,3-dimethylpyrazine was 22.16%.The yield of 2-methylpyrazine was 63.31%.