With the vigorous advancement of sponge city construction, many studies on runoff treatment and reuse of bio-retention systems have been carried out. In order to explore the removal mechanism of pathogenic microorganisms in bio-retention system and solve the problems in the simulation, the bio-retention system in recent years was reviewed from four aspects, namely the type and content characteristics of pathogenic microorganisms, removal effects and influencing factors, removal mechanism and model simulation. The results showed that the bio-retention system can effectively remove pathogenic microorganisms in runoff, but it is clear that its removal mechanism of pathogenic microorganisms, the construction of a more complete model to simulate the removal process of pathogenic microorganisms, and the optimal removal of optimal parameters are still the focuses of future research.