Objective To investigate the co-infection of pemphigus patients and to further analyze its influencing factors.Methods The clinical data of 105 patients with pemphigus admitted to Maoming People's Hospital from March 2019 to March 2021 were retrospectively analyzed.The current status of co-infection in patients with pemphigus was investigated,and the types of pathogens and influencing factors of co-infection were analyzed.Results In this study,a total of 47 patients with pemphigus were co-infected,and the co-infection rate was 44.76% (47/105).49 strains of pathogenic bacteria were isolated,among which Gram-positive bacilli(G+)were the most common,accounting for 59.18%,Gram-negative bacilli(G-)were the second,accounting for 22.45%,and fungi were the least common,accounting for 18.37%.The co-infection of pemphigus patients was not related to gender,disease type,hormone type,hypertension and hyperlipidemia (P＞0.05),but was related to age,disease course,disease severity,hypoproteinemia,diabetes mellitus and CD4+T lymphocytopenia (P＜0.05).The results of multivariate logistic regression analysis showed that hypoproteinemia,CD4+T lymphocytopenia,diabetes mellitus and severity of disease were independent influencing factors of co-infection in pemphigus patients (P＜0.05).Conclusion The incidence of co-infection in patients with pemphigus is high,and the main pathogens of infection are Gram-positive bacilli.Co-infection in patients with pemphigus is affected by multiple factors such as co-disease and severity of illness.Clinicians should take preventive measures to reduce the incidence of infection.