Last 2 year, we have established tilapia by-product hydrolysis procedure and isolated photosynthetic bacteria (PSB) in this project. This year, we combined hydrolysis and PSB technologies to produce live feed for fish fry culture trial. In vitro results of pathogen inhibition showed isolated PSB (Rhodopseudomonas palustris, EL strain) had great effect of competitive inhibition against Aeromonas hydrophila, Streptococcus agalactiae and S. iniae. Furthermore, PSB can also be applied on mutiple live feed culture, such as Brachionus sp., Cyclops sp. and Daphnia sp., offering different development stage fish fry. Next-generation sequencing results demonstrated comparing control group (natural fermentation method), experimental group (fish protein hydrolysate (FPH) combined PSB) had significantly lower relative abundance of Aeromonadaceae, which is consistent with In vitro results. It validated FPH combined PSB method can reduce the pathogen-carrying risk of live feed. Moreover, non-metric multi-dimensional scaling (NMDS) results showed within-group variance in experimental group was lower than in control group, indicating bacteria flora can effectively controled, and ensure the stability of ive feed quality. In aspect of proximate composition, the experimental group had significantly higher crude protein content, but significantly lower crude lipid. To evalute the benefits of these 2 live feed producrion method to practical fish fry culture, we conducted Bidyanus bidyanus fry feeding experiment for 25 days. The survival rate and growth performance of experimental group were significantly higher than that of control group by 20% approximately, validating the live feed culture method combined FPH and PSB not only can promote the reuse of fisheries by-product , but also has benefits on fish fry culture.