〔Abstract〕 Objective To explore the characteristics of the effects of radiation on the intestinal flora and the correlation between changes in the flora and the occurrence of radiation enteritis. Methods Thirty patients with cervical cancer admitted to Quanzhou First Hospital Affiliated to Fujian Medical University from January 2019 to January 2020 were selected. Fecal samples were collected at different time points during IMRT radiotherapy to analyze biomarkers of intestinal microecology. The DNA of intestinal flora was extracted with the MoBio PowerSoil kit. The V4 region of 16S rRNA of intestinal flora was sequenced and analyzed by MiniSeq. Wilcoxon rank sum test was used for difference degree. Results The alpha diversity of the intestinal flora after radiotherapy in patients with cervical cancer was higher than that before radiotherapy. At the same time, there were certain differences in the composition of the microbial community (ie, beta diversity) before and after radiotherapy, but the differences were not statistically significant (P > 0.05); After radiotherapy for patients with cervical cancer, we observed significant changes in the microbial composition of Prevotella and Streptococcus compared to before radiotherapy (P < 0.05). Conclusions There are differences in the microbial composition of cervical cancer patients before and after radiotherapy, but this needs to be confirmed by a large-scale prospective cohort study.