Objective To analyze the diagnostic value of application of capsule endoscopy (CE) followed by double-balloon enteroscopy (DBE) in small bowel diseases, and to explore the diagnostic concordance between CE and DBE, thereby optimizing the examination workflow for patients with suspected small bowel lesions. Methods A retrospective analysis was conducted on the clinical data of 154 consecutive patients who underwent CE followed by DBE at Renji Hospital, Shanghai Jiao Tong University School of Medicine, between January 2020 and March 2025. The diagnostic concordance between the two examination modalities were assessed, and the influence of age and lesion type on concordance was analyzed. Results For the 154 patients who underwent CE followed by DBE in this study, the lesion detection rate of CE was higher than that of DBE [93.5%(144/154) vs 81.8%(126/154), χ² = 8.53, P=0.003 5], and the detection rate of polyps/poly-poid hyperplasia by CE was higher than that by DBE (11.7% vs 5.2%, χ²=3.85, P=0.049). The detection rate of mass/submucosal lesions by DBE was higher than that by CE (5.84% vs 0.65%, χ²=6.4, P=0.011). Among the detected lesions, the detection rate of ulcerative diseases was highest (68/154), followed by inflammation/erosion, vascular malformation/blee-ding, polyps/polypoid hyperplasia, and mass/submucosal elevation. The overall diagnostic concordance between CE and DBE was moderate (κ=0.344, 95%CI 0.222-0.467, P<0.001), but higher concordance was observed for the diagnosis of ulcers (κ=0.55) and vascular malformation/bleeding (κ=0.42). After stratifying patients by age into 18 years (minors), 18-40 years (young adults), 40-59 years (middle-aged adults), and ≥60 years (elderly), the results of diagnostic consistency analysis showed that in the 40-59 years group, the diagnostic concordance rate between CE and DBE was 55.6% (κ=0.122), while in the 18-40 years group and the ≥60 years group, the diagnostic concordance rates were 46.20% (κ=0.447) and 44.10% (κ=0.446), respectively. Conclusions CE and DBE examinations are complementary in the diagnosis of small bowel diseases. CE can serve as a preliminary screening tool to optimize DBE examination. The sequentially combined application of the two can improve the diagnostic efficiency for small bowel vascular malformations and polyps. It is recommended to develop individualized sequential examination strategies based on patient age and lesion characteristics.