The invention discloses a gas chromatograph and detection method for determining the total content of sulfides in natural gas. The gas chromatograph comprises a quartz capillary column, a hydrogen flame ionization detector, a temperature control unit and a sulfur chemiluminescence reactor which are successively connected, wherein the quartz capillary column is a fused silica capillary column with uncoated inner walls; and the gas chromatograph further comprises a processor which is connected with the sulfur chemiluminescence reactor and a display unit. The gas chromatograph and detection method provided by the invention eliminate influence of hydrocarbons on determination of sulfide content, are more accurate in testing and have a wider application scope.