Objective: To explore the characteristics of adverse drug reactions during the 24-week therapy with delamanid-containing regimen for patients with multidrug-resistant and rifampicin-resistant pulmonary tuberculosis (MDR/RR-PTB). Methods: The prospective multicenter study was conducted from June 2020 to June 2023. A total of 608 eligible patients with MDR/RR-PTB were enrolled in 26 tuberculosis medical institutions in China including 364 males and 79 females, aged 39.6(19.0-68.0) years. Patients were treated with chemotherapy regimens containing delamanid. Patients were closely supervised during treatment of medication, and all adverse reactions occurring during treatment were monitored and recorded. The clinical characteristics of adverse reactions were evaluated by descriptive analysis. Chi-square test and multivariate logistic regression were used to analyze the related factors of QTcF interval prolongation (QT corrected with Fridericia's formula). Results: Of the 608 patients enrolled in this study, 325 patients (53.5%) reported 710 adverse events within 24 weeks of treatment. The top 6 most common complications were hematological abnormalities (143 patients, 23.5%), QT prolongation (114 patients, 18.8%), liver toxicity (85 patients, 14.0%), gastrointestinal reaction (41 patients, 6.7%), peripheral neuropathy (25 patients, 4.1%) and mental disorders (21 patients, 3.5%). The prolongation of QT interval mostly occurred in the 12th week after the first dose of medication. Serious adverse reactions occurred in 21 patients (3.5%). There were 7 patients (1.2%) with mental disorders, including 2 patients (0.3%) with severe mental disorders. Conclusions: The safety of dalamanid-based regimen in the staged treatment of MDR/RR-PTB patients was generally good, and the incidence of adverse reactions was similar to that reported in foreign studies. This study found that the incidence of QT interval prolongation in Chinese patients was higher than that reported overseas, suggesting that the monitoring of electrocardiogram should be strengthened when using drugs containing delamanid that may cause QT interval prolongation.