Abstract: In order to utilize the seafood mushroom residue, the composting fermentation experiment was conducted to produce the organic fertilizer by using the seafood mushroom residue and fresh duck manure as the primary raw materials, supplemented with plant ash, tea residue and microbial inoculant. In this paper, four formulations were designed in the experiment, which were formulation #1 (40% seafood mushroom residue + 50% duck manure + 5% tea residue), formulation #2 (45% seafood mushroom residue + 40% duck manure+10% tea residue), formulation #3 (40% seafood mushroom residue + 40% duck manure + 15% tea residue), and formulation #4 (40% seafood mushroom residue + 40% suck manure + 15% tea residue). Meanwhile, all the four kinds of formulations were all added with 5% plant ash and 0.02% microbial inoculant. The fermentation temperature, nutrient content, and the dynamic changes of culturable bacteria were studied during the composting fermentation process of four kinds of formulations. The results showed that the temperature in the fermentation process of the four formulations could reach more than 60℃. The organic fertilizer fermented from formulations #3 and #4 exhibited the total nutrient contents of 4.64% and 4.07%, and the organic matter contents of 34.80% and 33.07%, respectively, which meet China’s national standards for commercial bio-organic fertilizers. The population of mesophilic bacteria adapting to 35℃ and thermophilic bacteria adapting to 55℃ were significantly increased after the composting fermentation. Compared with the initial composting stage, the population of mesophilic bacteria increased by 1.39 to 1.93 times in the four formulations, while the population of thermophilic bacteria increased by 0.98 to 1.38 times. It concluded that formulation #3 demonstrated the optimal performance, followed by formulation #4.