Objective To analyze the frailty of patients with long-term maintenance dialysis （MD） and its influencing factors， and to explore the correlation of different dialysis modalities with the re-infection of novel coronavirus infection （COVID-19） and frailty syndrome. Methods Patients with regular dialysis in Nephrology Department of the Second Affiliated Hospital of Kunming Medical University from February to June 2023 were selected. A cross-sectional survey was conducted to collect clinical data of the patients， including dialysis modality（i.e. maintenance hemodialysis， abbreviated as hemodialysis， and continuous ambulatory peritoneal dialysis， abbreviated as peritoneal dialysis），and whether with re-infection of COVID-19. Patients were divided into 3 groups using Fried′s frailty phenotype （FP）： non-frailty group， pre-or-intermediate frailty group， and frailty syndrome group. The clinical characteristics of the FP were compared among the three groups. The correlation of frailty with clinical data， dialysis modality， re-infection of COVID-19 in each group was compared. Multifactorial logistic regression was used to analyze the factors influencing the development of frailty syndrome in patients. Results A total of 246 dialysis patients were included in this study， with 77 （31.3%） in the non-frailty group， 83 （33.7%） in the pre-frailty group and 86 （35.0%） in the frailty syndrome group. The frailty syndrome group showed characteristics of advanced age， high pre-dialysis creatinine level， low serum albumin level and combined pleural effusion （all P < 0.05）.There was no statistically significant difference in the comparison of frailty between the hemodialysis and peritoneal dialysis group（P = 0.960）.COVID-19 re-positive patients had higher frailty score than non-re-positive patients. Multifactor logistic regression showed that age， COVID-19 re-infection of COVID-19， serum albumin， pre-dialysis creatinine， and pleural effusion were factors influencing the development of frailty syndrome in dialysis patients（P < 0.05）. Conclusion There is high incidence of frailty syndrome in dialysis patients， and there is no correlation of frailty with dialysis modality. High serum albumin level is a protective factor for the development of frailty syndrome in patients， whereas re-infection of COVID-19， advanced age， high pre-dialysis blood creatinine level and pleural effusion are risk factors for the development of frailty syndrome.