PURPOSE: An environment-friendly feed additive, and a producing method of a fermented green tea probiotic are provided to prevent diseases of domestic animals and to promote the growth. CONSTITUTION: An environment-friendly feed additive is contained in a feed including crude protein or crude fat, crude fibers, and coarse ash, and includes 0.01~5wt% of fermented green tea probiotic. A producing method of the fermented green tea probiotic comprises the following steps: mixing 10% of green tea, 60% of defatted rice bran, and 30% of wheat bran, and injecting Lactobacillus plantarum and Lactobacillus acidophilus repeating processes of stirring and settling to perform aerobic and anaerobic fermentations for 2days for forming a first lactobacillus fermentation culture material and injecting Bacillus subtilis to the obtained fermentation culture material, and drying.본 발명은 사료 내 첨가된 항생제를 대체할 수 있도록 녹차와 유용미생물을 활용한 녹차발효생균제 등의 첨가로 항생제를 대체할 수 친환경 사료첨가제를 제공한다.