Sanghuangporus baumii, an edible fungus rich in heteropolysaccharides, has been found to have some anti-cervical cancer effects. In the current study, the effects of an aqueous extract of S. baumii on cervical cancer were investigated in a U14 cervical carcinoma cell implanted female Kunming mouse model. An aqueous extract of S. baumii (SHWE) was administered to tumor-bearing mice by gavage for 21 days. SHWE treatment significantly inhibited tumor growth by 67.4% at a dose of 400 mg per kg bodyweight. Transcriptomic results showed that the expression of key genes GABARAP, VMP1, VAMP8 and STX17 which are involved in the autophagy pathway was regulated after SHWE treatment, suggesting that SHWE may induce autophagy in tumors. The results were further confirmed by measuring the LC3II/LC3I ratio using western blotting. Moreover, some differentially expressed genes were involved in the insulin signaling pathway, implying that SHWE induced autophagy by disturbing glucose uptake and utilization in tumors. The analysis of the gut microbiota indicated that SHWE treatment stimulated the proliferation of Akkermansia, a well-known probiotic that presented benefits in metabolic regulation and cancer therapy. In conclusion, SHWE administration modified the gut microbiota, disturbed the glucose metabolism and induced autophagy in tumors, and then inhibited the development of cervical carcinoma in vivo.