The invention belongs to the technical field of 
isotope analysis and detection, and relates to a device for detecting 
sulfur isotopes in gas in a 
continuous flow mode. The device comprises a gas 
storage tank for storing a gas sample, a 
cold trap, an element instrument, an 
isotope mass spectrometer, a first 
helium conveying pipeline, a second 
helium conveying pipeline, a first gas inlet pipeline, an emptying pipeline, an 
oxygen conveying pipeline and a second gas inlet pipeline; the elemental instrument comprises an automatic 
solid sample 
injector, a 
combustion furnace and a reduction furnace;the first 
helium conveying pipeline, the gas 
storage tank, the 
cold trap, the first gas inlet pipeline, the 
combustion furnace, the reduction furnace, the second gas inlet pipeline and the 
isotope mass spectrometer are sequentially communicated; the 
cold trap is communicated with an emptying pipeline; the second helium conveying pipeline is communicated with the gas inlet end of the cold trap; andthe 
oxygen conveying pipeline is communicated with the 
combustion furnace. According to the device, a gas sample does not need to be pretreated, and the 
sulfur isotope in the gas sample can be calibrated by utilizing the 
solid standard substance.