The invention discloses a black carp feed for preventing and treating streptococcicosis and a preparing method thereof, wherein the feed is prepared from the following raw materials in parts by weight: 700-750 of Perilla oil meal, 6-10 of calcium gluconate,15-17 of garlic, 25-27 of mountain potato leaf, 35-38 of Soybean meal, 23-26 of oat powder, 5-6 of oyster sauce, 3-4 of honeysuckle flower, 4-5 of folium isatidis, 2-3 of fructus forsythiae, 37-42 of plasma protein powder, 36-38 of pawpaw powder, 15-17 of dry renewal, 4-6 of chicken bone soup, 3-4 of artemisiaannua powder, 16-18 of grenadine juice, 3-4 of emblic leafflower fruit powder, 4-5 of juicy peach powder, 5-6 of mint leaf powder, and 2-3 of activated clay. The feed in the invention has good disease resistance, can greatly improve an immune function of the black carp, enhance a self-healing function of the body, resist the streptococcal infection and damages, reduce prevalence rate and death rate; the feed is rich in nutrition, and can further reduce feed coefficient, quicken the growing speed of the black carp, and improve breed yield.