Abstract: The occurrence of shale gas is the core of shale gas accumulation.There are a series of problems with shale gas development in the main occurrence form,occurrence phase transformation,judgment of the adsorption carrier,and the contribution of each carrier to shale gas adsorption.It is not clear understanding of the adsorption mechanism and contribution of clay minerals in the shale gas reservoir.All of these problems bring a lot of uncertainty to the precise evaluation of shale gas resources.This paper describes the transformation characteristics of shale gas and the adsorption properties.It is pointed out that molecular simulation is an important and effective method for studying different adsorption vectors and their adsorption mechanisms in shale gas reservoir.The future study should focus on the geological process of the shale gas enrichment.And the key study would be on the gas enrichment of geological conditions and permeability of development technology.The geological condition is closely related to the occurrence of shale gas.The key factor is the coupling characteristics of methane gas and reservoir pore.The permeability of development technology is closely related to the permeability of the reservoir itself and the reconstruction of the reservoir.The good reservoir key characteristic lies in the adaptation characteristics of connectivity and scalability.Molecular simulation can explain the adsorption mechanism of shale gas at the molecular level,and can reveal the nature property of occurrence and enrichment of shale gas.It can well compensate for the lack of conventional experimental research on shale gas reservoir adsorption,and provide an effective method to make shale gas geology theory perfect.