The invention discloses a fermented organic fertilizer. The fermented organic fertilizer is prepared from, by weight, 30-50 parts of chicken manure, 40-55 parts of cow dung, 4-8 parts of crop straw, 1-5 parts of composite composted microbial agent and 1-5 parts of deodorant. The production process includes the steps of regulating the moisture content to 50-60% after evenly mixing the raw materials, piling the mixture into a long stack, conducting composting and fermenting for 20-30 days, and turning and throwing the stack through a turning and throwing machine and conducting oxygenation when the temperature of the stack is higher than 70 DEG C. The fermented organic fertilizer is free of pollution in the fermentation process and high in humification and harmless degree; the obtained fertilizer contains various types of beneficial microorganisms participating in growth of crops and is good in potency, and after the fertilizer is used, soil is improved, the soil fertility is improved, the immunocompetence of agriculture and forestry crops is improved, and the grain yield increase is achieved; during use, no putrid odor is generated, the use amount of chemical fertilizer is decreased, cost is saved, soil depletion, hardening and salinization can not be caused, and the fertilizer conforms to tendency of energy conservation, environment protection and sustainable development.