〔Abstract〕 Objective To investigate the effect of hysteroscopic cold knife technique in the treatment of intrauterine adhesions and its protective effect on the endometrium. Methods A total of 100 patients with intrauterine adhesions treated in Xiamen Haicang Hospital from January 2020 to December 2020 were randomly divided into a control group and an observation group, with 50 cases in each group. The control group was treated with hysteroscopic electrotomy, and the observation group was treated with hysteroscopic cold knife. Results After treatment, the levels of interleukin-4 (IL-4), interleukin-10 (IL-10), matrix metalloproteinase-9 (MMP-9), estradiol (E2) and endometrial thickness in the observation group were higher than those in the control group. The levels of interleukin-6 (IL-6), plasminogen activator inhibitor-1 (PAI-1), transforming growth factor-β₁ (TGF-β₁), luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), pulsatility index (PI) and resistance index (RI) in the control group were lower than those in the control group, the differences were statistically significant (P < 0.05). The hospitalization time and operation time of the observation group were shorter than those of the control group, and the intraoperative blood loss was less than that of the control group, and the differences were statistically significant (P < 0.05). The total effective rate and menstrual improvement rate of the observation group were higher than those of the control group, and the incidence of intrauterine adhesion was lower than that of the control group, and the differences were statistically significant (P < 0.05). Conclusion Cold knife technique under hysteroscope in the treatment of intrauterine adhesion can improve ovarian blood supply, regulate the levels of MMP-9, PAI-1 and TGF-β₁, and then regulate the expression of hormones, protect the endometrium, and prevent intrauterine adhesion again.