Objective: To investigate the infection of Helicobacter pylori (Hp) in peritoneal dialysis (PD) patients and the effect of Hp infection on their microinflammation and nutritional status. Methods: A total of 178 patients with continuous ambulatory PD admitted to Wanning People's Hospital from January 2016 to January 2020 were selected as the research objects. ¹⁴C-UBT was performed to determine the presence of Hp infection. The levels of C-reactive protei (CRP), albumin (ALB) and prealbumin (PAB) in serum were measured. The differences of the above indexes between Hp-positive and Hp-negative patients and the changes of the above indexes before and after anti-Hp treatment were compared. Results: The incidence of Hp infection in PD patients was 41.57%. The serum CRP level in the Hp-positive group was significantly higher than those in the Hp-negative group, while the serum Alb and PAB levels were significantly lower than those in the Hp-negative group, the difference was statistically significant (P<0.05). The serum CRP level in Hp-positive patients after anti-Hp treatment was significantly lower than those before the treatment, and the serum Alb and PAB levels were significantly higher than those before treatment. The difference was statistically significant (P<0.05). Conclusion: Hp infection in peritoneal dialysis patients can aggravate the microinflammatory state and malnutrition, and Hp eradication therapy is beneficial in improving both symptoms.