Objective To analyze the clinical characteristics of patients with SARS -CoV-2 Delta variant infection, provide reference for the prevention and treatment of Delta infection. Methods Clinical characteristics of 76 patients with SARS -CoV-2 Delta variant infection in Zhangjiajie Hospital Affiliated to Hunan Normal University from July to August 2021 were analyzed retrospectively. Results The outbreak involved 76 infected persons in 17 families, 8 working settings, with an average age of (34.7±18.1) years old, as well as a high incidence among population aged 15-49 years old. There were 4 asymptomatic infected cases (5.26%), 17 mild cases (22.37%), 50 common cases (65.79%), 4 severe cases (5.26%) and 1 critical case (1.32%); among 76 cases of SARS -CoV-2 Delta variant infection, the lowest Ct value N value of SARS -CoV-2 nucleic acid was 17.5, Lab value was 16.25, the average duration of positive of SARS -CoV-2 nucleic acid was 34.5 days, 23 of whom were positive for Ct value of SARS -CoV-2 nucleic acid again 7 days after discharge. The main clinical manifestations were fever and cough. In the early stage of infection, 98.68% of patients had normal or decreased white blood cell count, 11.84% of patients had slightly increased aspartate aminotransferase/alanine aminotransferase (AST/ALT), and few patients with abnormal creatinine and myocardial enzymes; the proportion of elevation of erythrocyte sedimentation rate (ESR), procalcitonin (PCT) and C-reactive protein (CRP) were 58.21%, 5.26% and 31.58% respectively. Among them, 55 cases (73.37%) suffered from lung lesions, which were characterized by ground glass shadows, mainly distributed along the subpleura, and some cases were complicated with pleural effusion and consolidation. Conclusion Patients with SARS -CoV-2 Delta variant infection have high viral load and long negative conversion time of nucleic acid, the main clinical manifestations are fever and cough, and the early stage may be accompanied by the increase of AST/ALT.