Over feeding in order to grow rapidly, fourfinger threadfin farming can easily cause intestinal pressure and often cause intestinal diseases. Drugs used such as antibiotics for treating enteritis frequently. The larval feed is added with the lactic acid bacteria Leuconostoc mesenteroides B4 , which produces glucans and oligosaccharides. The culture medium and granulated sugar and maltose are fermented to produce a synthetic probiotic product containing lactic acid bacteria and dextran, and a functional feed composed of probiotic Bacillus pumilus D5, a probiotic that has an antagonistic effect on Vibrio. The weight gain and feed conversion rate are better than those without supplementation. The growth of intestinal villi was observed. The control group showed atrophy and necrosis. The compound probiotics were fed daily and fed once every 2 days compared to feeding once every 3 days. The growth of villi is better. According to comprehensive evaluation, 0.1% compound probiotics are added to the noon larvae feed, and the feeding frequency is once every 2 days to achieve the effect of protecting the intestines and promoting growth.