In this paper, single-factor experiments and orthogonal experiment were conducted to optimize the water bath extraction of polyphenols from Qing Brick Tea, and the optimal extraction conditions obtained were as follows: solvent of 50% ethanol, solid/liquid ratio of 1: 30, temperature of 80 ℃, and time of 6 min. Under the optimal water bath extraction conditions, polyphenols in fresh tea leaves, fresh tea petioles, fresh tea blades, finished brick tea, finished tea petioles, finished tea blades, tea dregs after brewing and tea dregs after boiling were extracted, respectively. It was found that the quality fraction of polyphenols extracted from fresh tea leaves was the highest, with the best extraction effect. The extraction effect of leaf blades was better than that of leaf petioles, and the extraction effect of tea dregs after brewing was better than that of tea dregs after boiling.