Objective: In order to reuse the Areca catechu by-product—A. catechu pedicle, and improve the quality of mycelium of edible fungi, the effect of the pedicle aqueous extract on the liquid fermentation of edible fungi was investigated. Methods: Pleurotus ostreatus, Pleurotus citrinopileatus Singer, and Flammulina velutiper were selected as the test strains, and the effects of the addition of A. catechu pedicle aqueous extract on the quality of mycelium and the activity of enzymes related to the growth and metabolism of the three strains were investigated, by using mycelial growth rate, biomass, mycelial active ingredients and antioxidant activity as indicators. Results: The best growth effect was observed on the P. ostreatus, P. citrinopileatus and F. velutiper when 6.4, 4.8 and 4.8 mg/mL A. catechu pedicle aqueous extract was added, respectively. Compared with the control group, when adding 4.8～6.4 mg/mL A. catechu pedicle aqueous extract, the mycelium active ingredient content was significantly increased, and the mycelium triterpene content of P. ostreatus, P. citrinopileatus, and F. velutiper were increased by 95.24%, 70.91% and 75.00%, respectively. Moreover, A. catechu pedicle aqueous extract increased the antioxidant activity of mycelium, and the antioxidant capacity of mycelium was in the following order: P. citrinopileatus＞F. velutiper＞P. ostreatus; A. catechu pedicle aqueous extract increased the activities of amylase, cellulase, xylanase and laccase of the three strains to some extent, but the effect on the trend of enzyme activity was not significant. Conclusion: Adding the proper amount of aqueous extract of A. catechu pedicle can effectively improve the mycelial quality and the antioxidant activity of the three strains.