The invention relates to a method for analyzing the argon mass number abundance value and the specific value in argon by a GC-MS (gas chromatography-mass spectrometry) method. The method comprises the following steps: (1) enabling carrier gas with the purity greater than 99.99% to pass through a purifier so as to enable the purity of the purified carrier gas to be greater than 99.999%; (2) introducing the purified carrier gas into a chromatographic column in which a to-be-detected argon sample is arranged in a gas chromatograph, deoxidizing the to-be-detected argon sample in a nickel contact agent tube after adsorption and desorption effects, and finally measuring in a mass detector so as to obtain an ion flow chromatogram and a mass spectrogram respectively; and (3) acquiring the mass number abundance values of 20Ar, 36Ar, 37Ar, 38Ar, 40Ar, 41Ar and 42Ar in argon respectively by a selected ion method according to the ion flow chromatogram and the mass spectrogram, and determining the specific value according to the relative standard deviation RSD being less than or equal to 5%. The method provided by the invention can be applied to noninvasive detection of human health, human body medical science and animal and plant research.