Objective To compare the effectiveness of three kinds of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and sleeve gastrectomy combined with transit bipartition (SG+TB ) as three weight-loss surgical differences in weight loss and glucose control as well as alleviation of nephropathy in obese rats with diabetic nephropathy (DN). MethodsTwelve of 60 SD male rats were randomly selected according to their average body mass and fed with a standard diet (12% fat fever) as normal control (NC) group, and the remaining 48 were fed with high-fat diet (40% fat calories) for 1 month and combined with low-dose 1% streptozotocin method to induce the establishment of obese combined diabetic nephropathy rat model, and subsequently randomized equally into SG group, RYGB group, SG+TB group and sham-operated group. Body mass and food intake were weighed and the fasting blood glucose (FBG) level after fasting for 6 hours was detected before and every month at 1–6 months after operation. At the same time, oral glucose tolerance test (OGTT), insulin tolerance test (ITT), urinary albumin creatinine ratio (UACR), serum creatinine (Scr) and blood urea nitrogen (BUN) were tested before operation and at the 1st and 6th month after operation. Finally, rat kidney tissues were taken to observe the pathological changes. Results Body mass and food intake of the SG group, the RYGB group and the SG+TB group were lower than that of the sham-operated group at 1–6 months after operation (P<0.05). The body mass of the RYGB group and the ST+TB group were lower than that of the SG group at 1–6 months after operation (P<0.05). There was no significant difference in food intake among the SG group, the RYGB group and the SG+TB group (P>0.05). The FBG levels in the SG group, the RYGB group and the SG+TB group were lower than those in the sham-operation group at 1–6 months after operation (P<0.05). The FBG levels in the RYGB group and the SG+TB group were lower than those in the SG group at 4–6 months after operation(P<0.05). The blood glucose levels detected by OGTT and ITT in the SG group, the RYGB group and the SG+TB group after operation were all lower than those in the sham-operation group (P<0.05), and all were lower than before operation (P<0.05), and the blood glucose level detected by OGTT in the RYGB group at the 1st postoperative month was lower than those in the SG group and the SG+TB group (P<0.05). Whereas there was no significant difference in the blood glucose levels detected by OGTT at the 6-month postoperative period between the the RYGB group and the SG+TB group (P>0.05), but were lower than the SG group (P<0.05). The levels of UACR, Scr and BUN in the SG group, the RYGB group and the SG+TB group after operation were lower than those in the sham-operation group (P<0.05) and lower than those before operation (P<0.05). The UACR and Scr levels in the RYGB group and the SG+TB group were lower than those in the SG group at the 1st and 6th month after operation (P<0.05). There was no significant difference in BUN level among the SG group, the RYGB group and the SG+TB group after operation (P>0.05). Typical pathological changes of diabetic nephropathy occurred in the kidney of rats in sham operation group, such as glomerular edema, capillary cavity congestion and congestion, and mesangial matrix increase. The mesangial matrix of rats in the SG group, the RYGB group and the SG+TB group were significantly improved compared with that in the sham-operation group. Conclusion SG, RYGB and SG+TB can effectively reduce weight, reduce blood sugar and relieve diabetic nephropathy, and SG+TB and RYGB are better than SG.