A GC-MS method is provided with installing a sample injector; installing a heart-cutting unit; installing a first capillary column; connecting a switching valve to the heart-cutting unit; installing a capture and release device to the heart-cutting unit; connecting the capture and release device to the switching valve; connecting the switching valve to an MS; rotating the switching valve to either connect the first and second interconnecting columns, or connect the second capillary column and the second interconnecting column; injecting the sample gas into the first capillary column; by setting a time slot and carrier gas pressure of the heart-cutting unit, while causing fractions of simple compounds to be cut out and travel to the MS, causing fractions of complex compounds to be cut out; after the simple compounds finished in MS, causing complex compounds to be released from the capture and release device; and sending the compounds.