Objective: To evaluate the clinical efficacy of dydrogesterone combined with non-steroidal anti-inflammatory drugs(NSAIDs) in the treatment of patients with mild endometriosis.Methods: This was a clinical comparative study. Eighty patients with mild endometriosis were recruited at Affiliated Hospital of Hebei University, randomly divided experimental group (n=40) and control group (n=40) from March 2022 to March 2023. Both groups started treatment with dydrogesterone on the 5th day of menstruation. Patients in the control group were treated with dydrogesterone monotherapy, while those in the experimental group were treated with mefenamic acid the basis of the therapy of the control group. The clinical efficacy, differences in the levels of humoral immune indexes, the levels of inflammatory factor and the incidence of adverse drug reactions of the two groups was compared and analyzed.Results: The efficacy of the experimental group was significantly higher than the control group, with a statistically significant difference(P=0.02). The levels of C3 and C4 in the experimental group after treatment were significantly lower than those in the control group, with a statistically significant difference(P=0.00). After treatment, TNF-a, CRP, IL-6 and other indexes in the experimental group were significantly lower than those in the control group, with statistically significant differences(P=0.00). The incidence of adverse reactions after treatment had no statistically significant difference(P=0.45).Conclusion: Dydrogesterone combined with non-steroidal anti-inflammatory drugs is a safe and effective treatment for patients with endometriosis. It can improve various obvious curative effects, such as marked relief of pain symptoms, reduction of complement and inflammatory factor levels without a significant increase in adverse reactions.