The present invention relates to an environment-protecting type mixed feed for making low-salinity culture of Fanna prawn. The raw material composition of said feed includes (by wt%) 20-40% of red-fish powder, 10-20% of soybean dregs, 7-16% of peanut shell meal, 3-8% of bone powder, 5-10% of shrimp bran, 4-10% of cotton seed cake, 4-10% of cuttle-fish guts powder, 18-25% of glutenous flour, 1.0-2.0% of soybean lecithin, 1.0-2.0% of sea-fish oil, 0.2-0.5% of choline chloride, 0.05-0.1% of vitamin C-organic phosphate, 0.5-1.0% of calcium dihydrogen phosphate, 0.2-0.5% of compound polyvitamin and 0.3-1.5% of compound mineral salt. Said feed is high in conversion rate, and its feed coefficient is 0.9-1.3.