Leukemia has become an important threat to human health, and infection complications are the main obstacle to the clinical leukemia treatment. The intestinal barrier integrity was damaged due to the tumor characte-ristics of leukemia and high-intensity chemotherapy, intestinal bacterial translocation is an important cause for bloodstream infection. Mucosal barrier injury laboratory-confirmed bloodstream infection (MBI-LCBI) is an important component of bloodstream infection in patients with acute leukemia, but relevant research is very limited. The paper reviews the mucosal barrier injury, bacterial translocation, as well as the definition, diagnosis and prevalence of MBI-LCBI, analyzes the mechanism of intestinal microecology in regulating intestinal mucosal barrier integrity and effect of MBI-LCBI, aiming to provide theoretical basis for prevention, treatment and management of chemotherapy-induced mucositis and MBI-LCBI.