Objective To systematically review the effect of bariatric surgery for male’s erectile function. Methods We electronically searched databases including PubMed, EMbase, The Cochrane Library (Issue 5, 2016), CNKI, VIP and WanFang Data from inception to May 30th 2016, to collect randomized controlled trials and before-after studies about bariatric surgery therapies for erectile function in obese male. Two reviewers independently screened literature, extracted data, and assessed the methodological quality of included studies. Then RevMan 5.3 software was used for meta-analysis. Results A total of 7 before-after studies involving 270 patients were included. The results of meta-analysis showed that: compared with before treatment, bariatric surgery could significantly improve 1-year erectile function score (MD=5.05, 95%CI 3.52 to 6.59, P < 0.000 01), 1-year sexual desire score (MD=0.99, 95%CI 0.47 to 1.51, P=0.000 2), 1-year contact satisfaction score (MD=2.70, 95%CI 0.21 to 5.19, P=0.004) and 1-year total satisfaction score (MD=1.68, 95%CI 0.27 to 3.09, P=0.002), but there was no significant difference in orgasm function score (MD= –0.21, 95%CI –0.74 to 0.33, P=0.45) between before and after treatment. Conclusion Bariatric surgery is effective in improving the erectile function, sexual desire and sexual satisfaction in morbidly obese male. Due to the limited quality and quantity of the included studies, the above conclusion needs to be verified by more large-scale high-quality studies.