Abstract: To investigate the influence of yeast inoculation on pummelo（Citrus maxima）enzymes, the dynamic changes of key physicochemical indices and viable cell counts were monitored throughout fermentation. Cracked pummelo fruits served as raw material; a natural-fermentation batch acted as control, while a parallel batch was inoculated with yeast. Both batches were analyzed for viable yeasts and lactic-acid bacteria, pH, organic acids, total phenolics, protease and β-glucanase activities.In terms of the fermentation cycle, the experimental group completed the rapid proliferation of microbial flora, polysaccharide degradation, and efficient accumulation of organic acids and total phenols within the first 35 days of fermentation. After 35 days, all indicators stabilized, shortening the fermentation cycle by 55 days compared to the 90-day cycle of the control group. Organic acids and total phenolics accumulated rapidly during the early phase at 45 d the organic-acid concentration was 43.75 % higher（P ＜ 0.05）, and at 35 d the total-phenolic content was 55.6 % higher（P ＜ 0.05）than in the control. Peak activities of protease（9078 U·L⁻¹）and β-glucanase（3321 U·L⁻¹）appeared at 35 d and 60 d, respectively, both significantly surpassing the corresponding control values（P ＜ 0.05）. Viable counts in the inoculated batch were also significantly superior（P ＜ 0.05）, reaching 6.0 × 10¹³ CFU·mL⁻¹ for yeast and 5.5 × 10¹⁰ CFU·mL⁻¹ for lactic-acid bacteria.In conclusion, yeast-inoculated mixed fermentation not only shortens the process but also enhances the functional quality of pummelo enzymes, validating the feasibility of a “natural fermentation plus exogenous yeast” strategy for cracked-fruit valorization and providing a scientific basis for high-value utilization of pummelo-processing waste.