The invention provides Athetis lepigone larva feed, which is made of, in weight percentage, 1-15% of cornmeal, 2-10% of soybean meal, 1-10% of yeast powder, 0-5% of wheat germ flour, 0-5.0% of casein, 0-5.0% of corn leaf powder, 0.1-2.0% of sorbic acid, 0-1.0% of formaldehyde, 0-2.0% of citric acid, 0-1.0% of vitamin B complex, 0-0.5% of ascorbic acid, 0-0.05% of cholesterol, 0-0.5% of choline chloride, 0.1-5.0% of cane sugar, 0.1-5.0% of agar and the balance of distilled water. The invention further provides a preparation method of the Athetis lepigone larva feed, which includes adding the distilled water to cook the agar and the cane sugar, adding the cornmeal prior to boiling, and adding the sorbic acid and the like after boiled stuff is removed from fire. The Athetis lepigone larva feed is applicable to feeding larvae of Athetis lepigone, survival rate of the larvae and egg laying amount of next-generation adults can be increased, and sufficient insect sources are provided for laboratory study of the Athetis lepigone.