【Objective】The effects of earthworm bio-organic fertilization（FBO） on quality of Jinxuan green tea and its mechanism were researched， in order to provide a theoretical basis for the application of FBO in the tea garden soil fertilization. 【Method】A long-term experiment was carried out. Tea leaf yield and sensory evaluation comprehensive score were compared between two earthworm bio-organic fertilization treatments（100% FBO and 50% FBO） and conventional fertilizer treatment（CK）. And the change of water extract， tea polyphenol， amino acid，soluble sugar，tea caffeine and tea polyphenol- amino acid ratio were analyzed. 【Result】The application of FBO could significantly improve the comprehensive tea quality by 3.5%-5.7%（P<0.05， the same below） without production reducing， significantly reduce tea caffeine content， and slightly increase soluble sugar content. The total amount of amino acid in earthworm FBO treatment was lower than that of CK because of lower nitrogen inputs. Principal component analysis showed that， the contribution rate of the first principal component was 46.56%， that of the second principal component was 30.46%. The indicator that contributed the most to the first principal component was tea caffeine， and the one contributed the most to the second principal component was soluble sugar. In another words， the reason earthworm FBO could improve tea quality was mainly related to tea caffeine content reduction and soluble sugar content increase. 【Conclusion】The application of organic fertilizers+earthworm inoculation in tea plantation can completely or partially replace fertilizer， which can reduce the amount of fertilizer， and promote the production and quality of Jinxuan green tea. The FBO technology can be applied to tea production.