Non-erosive gastroesophageal reflux disease (NERD) refers to a disease with symptoms such as acid reflux, heartburn and pathological reflux, but no significant esophageal mucosal damage under endoscopy. Its pathogenesis may be related to factors such as lower esophageal sphincter dysfunction, weakened esophageal clearance ability, visceral hypersensitivity, and disordered intestinal microecology, but the specific mechanism is still unclear. Small intestinal bacterial overgrowth (SIBO) is a common intestinal flora disorder syndrome. A number of studies have shown that SIBO has a certain correlation with NERD, and SIBO may be involved in the occurrence and development of NERD through mechanisms such as inflammatory response, gas production, and increased short-chain fatty acids. Therefore, this article reviews the correlation between NERD and SIBO, aiming to provide new ideas for the diagnosis and treatment of NERD.