The invention provides a fodder for improving breeding efficiency of beet armyworm. The fodder comprises corn flour, yeast powder, citric acid, sodium benzoate, cane sugar, Vitamin C, folium mori, angelica sinensis powder, semen cassia powder and water; on the basis of traditional beet armyworm fodder, angelica sinensis powder and semen cassia powder are added to combine with folium mori; thus the fodder can improve the immunity of beet armyworm, and reach the effects of improving the survival rate, pupation rate and eclosion rate of beet armyworm larva; through detection, the breeding efficiency of the beet armyworm cultivated by the fodder of the invention can be improved by over 10%.