Abstract: Imbibition has gradually become a crucial mechanism for enhancing oil recovery in unconventional and low-permeability fractured reservoirs. The existence of a large number of fractures and the development of small pores provide favorable conditions for imbibition. This paper categorizes the imbibition mode based on the contribution of capillary force and gravity to imbibition. It elaborates in detail on the impact laws and mechanisms of factors such as reservoir type, pore permeability properties, boundary conditions, and fluid (including crude oil and infiltration liquids) properties on infiltration focuses on various factors that affect infiltration, and summarizes various experimental methods currently used to study infiltration. Finally, based on the progress in imbibition research, we discuss and look forward to the research prospects in selecting experimental conditions, the influence of clay hydration, optimising interfacial tension, and determining imbibition patterns.