Objective: Magnetically controlled capsule gastroscopy (MCCG) is an effective method for screening gastric diseases; however, its performance may be affected by gastric cleanliness. We aimed to explore the correlation between Helicobacter pylori infection and the degree of gastric cleanliness in the MCCG. Methods: This retrospective study enrolled 297 participants from October 2020 to April 2024 at Sir Run Run Shaw Hospital, Zhejiang University School of Medicine. Participant characteristics, MCCG examination results, and (13) C-urea breath test (C13-UBT) results were collected. The gastric cleanliness in MCCG examinations was assessed using a gastric cleanliness score. Binary logistic regression was used to analyze the relationships among participant characteristics, H. pylori infection, and gastric cleanliness. Chi-square tests and Fisher's exact tests were used to analyze the relationships among gastric lesions, H. pylori infection, and gastric cleanliness. Results: Among the participants, 24.2% had H. pylori infection, and 17.5% had poor gastric cleanliness. Hypertension (odds ratio [OR]: 2.63; 95% confidence interval [CI]: 1.36–5.09; p = 0.004) was associated with a greater likelihood of H. pylori infection. H. pylori infection (OR: 3.76; 95% CI: 1.99–7.09; p