The static headspace gas analytical technique is mainly devoted to the analysis of physically adsorbed and dissolved light hydrocarbons whose composition and content can directly reflect oil and gas information of the underlying strata. When used to surface geochemical exploration,it can predict and judge the position and properties of the transverse profile of the oil gas horizon;when employed to borehole geochemical exploration,it can accurately predict and judge the position and properties of the longitudinal profile of the oil-gas horizon based on the composition and content of the light hydrocarbon.