Imbibition occurs in porous media, the process of spontaneous absorption of wet-phase fluid is called imbibition, which is an effective method to exploit unconventional oil and gas reservoirs. Rational utilization of imbibition process can improve oil and gas recovery. With the continuous development of unconventional oil and gas, including shale oil, the imbibition process of shale reservoir has become the focus of international research. In this paper, the research progress of imbibition characteristics of shale oil and gas in recent years is reviewed, the mechanism of imbibition displacement in shale reservoir is described, and the production characteristics of shale oil in different pore sizes during imbibition are discussed. The influences of temperature, pressure, surfactant and permeability on the imbibition behavior of shale oil are summarized. This study reviews the mechanism of shale oil imbibition recovery, points out the existing problems of shale oil imbibition, and provides some theoretical support for the efficient exploitation of shale oil in the future.