We evaluated the weight loss effect of laparoscopic sleeve gastrectomy (LSG) and jejunal bypass (JJB) in treating obesity by analyzing and comparing the effects of LSG with or without JJB. A retrospective analysis was performed on the data of 150 patients with obesity who underwent bariatric metabolic surgery in Affiliated Xiaolan Hospital,Southern Medical University from October 2014 to April 2019. The patients were divided into two groups, LSG and LSG + JJB, according to the different surgical methods. The differences in the percentage of excess weight loss (%EWL) and total weight loss (TWL) between the two groups were statistically analyzed. The %EWL of the patients in the LSG group reached the maximum value at one year and six months post-surgery and steadily decreased after two years post-surgery. In contrast, the %EWL of the patients in the LSG + JJB group gradually increased after two years post-surgery; however, no significant difference between the two groups was observed. The TWL in the LSG + JJB group was significantly greater than that in the LSG group at each follow-up point. Postoperative %EWL was similar in both groups. The TWL in the LSG + JJB group was greater than that in the LSG group, and the postoperative recurrent weight gain rate in the LSG + JJB group was lower than that in the LSG group.