Abstract: Objective: To establish a method for simultaneous determination of nine active components in the fermented tea of Trametes versicolor, and analyze the changes of nine active components and antioxidant activities fermentation before and after. Methods: Using gradient elution at a flow rate of 1.0 mL/min, an Agilent C18 column (4.6 mm×250 mm, 5 μm) was used with a mobile of 0.05% phosphoric acid solution (A) and acetonitrile (B) as the mobile phase. The detection wavelength was 280 nm and the column temperature was 30 ℃. Results: Compared with the control group unfermented green tea, there was no significant change in the caffeine content of fermented tea. The increasing rates of gallic acid, theobromine and gallatechin gallate content in fermented tea were 0.4613%, 0.3118% and 0.5770%, respectively. The decreasing rates of egallatechin, theophylline, epigallocatechin, epicatechin and epigallocatechin gallate content in fermented tea were 0.0156%, 0.0178%, 1.2938%, 1.1062% and 4.0241%, respectively. In vitro antioxidant activity studies revealed that DPPH· scavenging capacity and ·OH scavenging capacity were significantly decreased after fermentation. When the concentration of Trametes versicolor fermented tea extract was 2.0 mg/mL, the scavenging capacity of DPPH· and ·OH was 7.79% and 9.65% respectively. Conclusion: The solid fermentation of Trametes versicolor can change the tea content of active ingredients and antioxidant activity, which provides experimental basis for the development of Trametes versicolor fermented tea.