Fish meal was prepared by microorganism solid-state fermentation using residues of aquatic products as raw material after optimization of the preparation conditions. With the total nitrogen content as an examining index, a single-factor experiment for accessories, inoculum size, fermentation temperature, fermentation time and oxygen content was conducted. The results showed that the optimum fermentation conditions were as follows: accessories of 1%, inoculum size of 6%, fermentation temperature of 30 ℃, fermentation time of 96 h and aerobic fermentation. Under these conditions, the total nitrogen content in the fermentation products reached 3 462.67±50.45 mgN/100 g. After vacuum freeze drying, the crude protein content was 61.59%, which reached the national first grade standard.