Microbial oil recovery mechanisms include hydrocarbonophilic viscosity reduction，emulsification，wettability alteration，and gas production. In the microbial wettability mechanism，microorganisms and metabolites modify the reservoir interface to improve oil displacement efficiency and crude oil percolation capacity. The current research progress in the role and micro-mechanism of microorganisms and metabolites in wettability modification was summarized，and the problems and development directions of microbial oil recovery technology，which require in-depth research for wettability modification，were presented. Current studies have confirmed that the microbial cells and metabolites can change the wettability of the rock surface to varying degrees，and the reasons for this phenomenon may be as follows：①The biological surfactant produced by microbial metabolism is adsorbed on the rock surface through the cleaning or covering mechanism，thereby changing the wettability of the rock surface. ②Microbial cells grow and multiply on the oil-water or oil-solid interface to form a viscoelastic biofilm，thereby completing wettability alteration. Due to the complex multi-mechanism synergistic reaction of the microbial oil recovery mechanism，the contribution of the biological wettability mechanism to enhanced oil recovery and the adaptability of oil reservoirs have not yet been clarified. Therefore，it is necessary to deepen the research on the wettability mechanism of microorganisms and metabolites and clarify its scope of action，stability，and reservoir adaptability to provide theoretical support for improving the field application of microbial oil recovery.