Objective To explore the risk factors of non-suicidal self-injury （NSSI） in depressive disorder with mixed features （DMX）. Methods A total of 100 patients with DMX who visited the Depression Clinic of Beijing Anding Hospital affiliated to Capital Medical University from May 4， 2021 to July 29， 2022 were selected as the research subject. Patients were divided into NSSI group （n=39） and non-NSSI group （n=61） based on whether NSSI occurred. The depression， anxiety， manic severity， and suicide ideation risk of patients were evaluated using four other-rating scales， including the 17-item Hamilton Depression Rating Scale （HAMD- 17）， Hamilton Anxiety Scale （HAMA）， Young Mania Rating Scale （YMRS）， and Columbia Suicide Severity Rating Scale （C-SSRS）. The severity of depression， anxiety， and anhedonia in patients was evaluated using three self-assessment scales， including the Patient Health Questionnare 9-item Scale （PHQ-9）， Generalized Anxiety Disorder 7-item Scale （GAD-7）， and Snaith-Hamilton Pleasure Scale （SHAPS）. Multivariate Logistic regression model was used to analyze the risk factors for NSSI in patients with DMX. Results There was a statistically significant difference between the two groups in terms of age， residential pattern， age of onset， HAMD-17 score， PHQ-9 score， SHAPS score， and suicide ideation risk level （P＜ 0.05）. Multivariate Logistic regression analysis showed that young age ［OR=0.900， 95%CI （0.829， 0.977）， P=0.012］， high HAMD-17 score ［OR=1.361， 95%CI （1.013， 1.829）， P=0.042］， and high SHAPS score ［OR=1.147， 95%CI （1.078， 1.215）， P ＜ 0.001］ were risk factors for NSSI in patients with DMXs. Conclusions Young age， severe depression， and severe anhedonia are risk factors for NSSI in patients with DMXs， and attention should be paid to DMX patients with this feature in the clinic and early intervention should be made to minimize the occurrence of NSSI.