Objective To provide an comprehensive evaluation of the correlation between sleep apnea hypopnea syn?drome (SAHS) and nonalcoholic fatty liver disease (NAFLD). Methods The various case-control studies on the relation?ship between SAHS and NAFLD were retrieved from all kinds of large-scale databases at home and abroad (including Web of science, EMbase, Pubmed, Springer Link, EBSCO Databases, CNKI, CQVIP, Wanfang Data). The quality evaluation of in?cluded studies was made by two independent researchers. RevMan 5.1 and stata 12.0 software were used for meta-analysis. Results A total of 11 qualified documents were included in this study. Meta analysis showed that the relative risk of NAFLD was increased in SAHS patients than non-SAHS patients (RR=2.82, 95%CI:2.03-3.92, P<0.01). The serum ala?nine aminotransferase (ALT) increased in SAHS patients (SMD=0.53, 95% CI:0.02-1.05, P < 0.05). Compared with non-SAHS patients, the apnea-hypopnea index (AHI) was significantly higher in SAHS patients combined with severe NAFLD than those combined with mild NAFLD (SMD=1.42, 95%CI:0.12-2.72, P < 0.05). Conclusion The risk of NAFLD in?creases in SAHS patients. The severity of NAFLD is relatively higher with the severity of intermittent hypoxia.