Objective To compare the bowel preparation quality and diagnostic value between traditional capsule endoscopy (CE) and diving CE. Methods Clinical data of 60 consecutive patients with suspected small bowel diseases who underwent CE from March 2016 to March 2017 were retrospectively analyzed. The first 30 patients had traditional bowel preparation (traditional CE group) while the rest 30 had diving bowel preparation (diving CE group). Bowel preparation scores, gastric transit time (GTT), small bowel transit time (SBTT), CE completion rate and lesion detection rate were calculated and recorded. Results The mean bowel preparation score was significantly lower in the traditional CE group (2.56±0.71) than in the diving CE group (3.24±0.71)(t=3.768，p<0.001). The mean GTT and SBTT in the traditional CE group were 40.86±35.91min and 314.20±151.30min, respectively. They were not significantly different from the mean GTT (52.82±38.96min) and SBTT (282.44±123.23min) in the diving CE group (p=0.233, p=0.392). The CE completion rate was 100% in the traditional CE group as compared with 90% in the diving CE group (p=0.237). The lesion detection rate in the traditional CE group was 73.3% (22/30), which did not differ significantly with that in the diving CE group (80%, 24/30, χ２=0.373，p=0.542) Conclusion Diving CE improves bowel preparation quality with a trend of higher lesion detection rate than the traditional CE.