To summarise the clinical characteristics of patients with Stevens-Johnson syndrome/toxic epidermal necrolysis syndrome (SJS/TEN) and analyse the efficacy and safety of systemic glucocorticoid therapy. Methods: This study was a retrospective study of 56 patients with SJS/TEN who had been systematically treated with glucocorticoids in the dermatology ward of Peking University Third Hospital from 2010 to 2020. The clinical characteristics, treatment regimen, effects on underlying diseases, incidence and outcome of hormone-related adverse reactions and skin lesion prognosis were summarised and analysed for each patient. Results: ① The allergenic drugs were found to be antibiotics (31.51%), antipyretic and analgesics (21.92%), traditional Chinese medicines and health products (15.07%) and neuropsychiatric drugs (13.70%). ② Based on the 56 patients' scores of toxic epidermal necrosis at admission, the actual mortality rate was 1.8% (1/56), which was significantly lower than the average expected mortality rate of 15.0% (P = 0.032; standardised mortality ratio = 0.13; 95% confidence interval: 0.00-0.53). ③ A total of 33 patients (58.9%) had underlying diseases, of which 10 patients (30.3%) had underlying diseases that fluctuated during treatment but stabilised after symptomatic treatment. ④ During treatment, 73.2% (41/56) of patients had complications that may have been related to systemic glucocorticoids; 97.6% (40/41) had mild symptoms, and 92.7% (38/41) had improved/recovered complications at the time of discharge. Conclusion: ① Antibiotics are still the most common sensitising drugs, and traditional Chinese medicine and health products are also common sensitising drugs. ② Early systemic application of medium-to high-dose glucocorticoids is effective in the treatment of SJS/ TEN, and it is beneficial in reducing mortality. ③ The short-term application of medium-to high-dose hormone therapy for SJS/TEN has little effect on underlying diseases. The related complications are mostly mild, and the treatment is safe.