Objective:To understand the clinical characteristics of novel coronavirus reinfection and explore the risk factors of novel coronavirus reinfection.Methods:The clinical data of 340 patients with novel coronavirus infection who were admitted to the Fever Clinic of Beijing Traditional Chinese Medicine, Capital Medical University from December 2022 to January 2023 were included. The general characteristics, basic diseases, clinical symptoms, and examination results of the first and second infections in the non repeated infection group, the repeated infection group, and the repeated infection group were compared. Binary logistic multivariate analysis was used to explore the risk factors of novel coronavirus reinfection.Results:In this study, 340 patients with novel coronavirus infection were included, 180 of whom were repeatedly infected. There was no statistically significant difference (all P>0.05) in terms of gender, age, body mass index (BMI), exercise, smoking, daily routine, and underlying disease between the recurrent infection group and the non recurrent infection group. However, the vaccination rate of the recurrent infection group was lower than that of the non recurrent infection group [80.0%(144/180) vs 88.0%(142/169), P<0.05]; In the repeated infection group, 157 cases (87.2%) were accompanied by overall discomfort (including headache, fatigue, muscle and joint pain), which was significantly higher than 122 cases (76.2%) in the non repeated infection group. The proportion of pneumonia occurring during the first infection was higher than that in the non repeated infection group [15.6%(28/180)], and the difference was statistically significant ( P<0.05). The interval between the first and second infections in the repeated infection group was (166.2±8.3)days. Cough and phlegm were the main clinical manifestations of two infections; The duration of re infection was shorter than that of the first infection [(7.03±2.30)days vs (8.94±3.02)days, t=6.739, P<0.001]; Secondary infections had less incidence of pneumonia [5.0%(9/180) vs 15.6%(28/180), χ 2=10.874, P=0.001]; 153 patients (85.0%) reported milder secondary infections. The results of binary logistic regression showed that cough, expectoration, body discomfort and pneumonia during the first infection were risk factors for repeated infection of novel coronavirus ( OR=2.710, 2.293, 2.808, P<0.05), and vaccination was a protective factor to avoid repeated infection ( OR=0.470, P=0.019). Conclusions:The symptoms of novel coronavirus reinfection are generally mild and the course of disease is relatively short. For vulnerable people, novel coronavirus vaccine should be actively inoculated to strengthen protection.