In order to study effects of lactic acid bacteria fermentation on the main components of Wuyi rock tea, the caffeine content of Wuyi rock tea before and after the change of lactic acid bacteria fermentation was analyzed. The results showed that at 37 ℃ fermentation temperature, fermentation time was 48 h, the inoculation amount was 6.8×103CFU / mL,the content of gallic acid in lactic acid bacteria fermentation liquid tea reached the highest of 16.76 mg / g, indicating that the fermentation of lactic acid bacteria had a certain influence on the content of gallic acid in tea. With the increase of the the fermentation of lactic acid bacteria, the caffeine content had an unobvious down-trend. The chelation ability of FEC was evaluated and the result showed that Wuyi rock tea had a high antioxidant effect.