Abstract: Bloodstream infection (BSI) is a systemic disseminated infection caused by various pathogenic microorganisms (bacteria, fungi, viruses, etc) or toxins entering the bloodstream, which is a serious threat to human life and has a very high mortality rate. Nowadays, the gold standard for the diagnosis of bloodstream infection is still blood culture, but the long testing period and low positive rate cannot meet the requirements of rapid diagnosis of early bloodstream infection, and the early use of effective antibiotic treatment can significantly improve the survival rate of patients. In recent years, with the development of molecular diagnostic technology, which makes up for the limitations of blood culture, it is mainly divided into molecular methods for identifying pathogens in blood cultures and molecular methods for directly identifying pathogens in whole blood samples, which have their own advantages in different scenarios. This study summarizes the progress in the molecular detection of pathogens in BSI.