Abstract: A preparation method of Cu—Pd—CeO2/?-Al2O3@NP catalyst and a synthesis method of benzopyrazine compounds. The preparation method of the Cu—Pd—CeO2/?-Al2O3@NP catalyst comprises the following steps: (1) preparing a CeO2/?-Al2O3 carrier; (2) preparing a CeO2/?-Al2O3@NP carrier; (3) preparing the Cu—Pd—CeO2/?-Al2O3@NP catalyst by impregnation method. A one-pot method for synthesizing benzopyrazine compounds of formula (III) includes using an o-nitroaniline compound of formula (I) and an aliphatic diol compound of formula (II) as raw materials, carrying out the one-pot synthesis of the benzopyrazine compound of formula (III) under solvent-free condition and under the combined action of the Cu—Pd—CeO2/?-Al2O3@NP catalyst prepared by the method and an alkali. The Cu—Pd—CeO2/?-Al2O3@NP catalyst increases the number of basic sites by doping N and P, and meanwhile loads CeO2 to assist in the extraction of protons, thereby improving the dehydrogenation activity and product selectivity.