Abstract: Soluble gaseous hydrocarbons and benzene homologues in groundwater is the direct indicator of hydrochemical to find oil. The direct extraction method is used in this text to test C1-C4 hydrocarbon gases and benzene homologues at the same time in the chromatography. Compared with the traditional test methods. The direct extraction has non-toxic, pollution-free, simple, rapid, high sensitivity, good repeatability, high degree of automation features, and has high practical value.