Objective To investigate the relationship between the cardia morphology under magnetically controlled capsule gastroscopy and the clinical characteristics of subjects. Methods A total of 216 subjects with gastrointestinal symptoms or receiving physical examination who underwent magnetically controlled capsule gastroscopy at the Department of Gastroenterology, Beijing Chao-Yang Hospital, Capital Medical University from August 2022 to November 2022 were enrolled. All subjects took gastroesophageal reflux disease questionnaire (Gerd-Q) survey. Clinical data of subjects were collected, and images of cardia morphology under magnetically controlled capsule gastroscopy were recorded. The subjects were divided into 4 groups according to differrent cardia morphology based on the degree of relaxation. The clinical characteristics of each group were compared, and the influencing factors for cardia morphology were analyzed. Results In non-swallowing state, 116 subjects showed good continuous closure of the cardia in plum shape (group A), 33 subjects radial closure of cardia (group B), 46 subjects slightly relaxed linear cardia (group C) and 21 subjects relaxed and continuous opening of cardia in the shape of cave (group D). The ages of subjects in group A, B, C and D were 35.00 (31.00, 42.00) years, 53.00 (37.50, 60.50) years, 61.50 (41.50, 68.25) years and 52.00 (39.00, 70.00) years, respectively, with significant differences (H=44.348, P<0.001). The Gerd‑Q scores of subjects in group A, B, C and D were 1.50 (1.00, 2.00), 3.00 (2.00, 6.50), 8.00 (5.75, 9.00) and 8.00 (7.50, 9.00), respectively, with significant differences (H=90.788, P<0.001). The body mass index (BMI) of subjects in group A, B, C and D were 22.66 (19.53, 24.70) kg/m2, 23.44 (21.41, 27.05) kg/m2, 23.77 (21.19, 26.93) kg/m2 and 23.73 (19.63,24.79) kg/m2, respectively, with significant differences (H=8.114, P=0.044). The degree of cardia relaxation was positively correlated with the age (rs=0.456, P<0.001), Gerd-Q score (rs=0.648, P<0.001) and BMI (rs=0.146, P=0.032) of subjects. Conclusion The magnetically controlled capsule gastroscopy provides good visualisation of cardia morphology in non-swallowing state. There is a positive correlation between the degree of cardia relaxation under magnetically controlled capsule gastroscopy in non-swallowing state and the subjects'' age, Gerd-Q score, and BMI.