The present invention provides a feed for improving resistance of red swamp crayfish and a preparation method thereof, and belongs to the field of feeds. The feed comprises component 1, component 2 and component 3; the component 1 comprises the following raw materials in parts by weight: fish meal, fermented soybean meal, corn flour, yeast powder, dried distiller's grains, organic vegetable powder, methionine selenium, spirulina platensis powder, pine needle powder, multivitamins and compound minerals; the component 2 comprises the following raw materials in parts by weight: shell powder, silkworm chrysalis meal, earthworm powder and margarya melanioides powder; and the component 3 comprises the following raw materials in parts by weight: membranous milk vetch root, cyrtomium rhizome, sessile stemona root, zedoray rhizome, dried tangerine peels, heartleaf houttuynia herb, pilose asiabell root, common andrographis herb, raw tobacco leaves, humifuse euphorbia herb, chinaberry seeds, burdock, haws, wild chrysanthemum, cloves and purple perilla. The feed is rich in the raw materials, balanced in nutrition, in line with nutritional needs of growth of the red swamp crayfish and high in absorption and utilization rate, enhances immunity, reduces disease occurrence, promotes growth and development, and increases yield.