The invention discloses a detection method for clopidogrel hydrogen sulfate related substance specific impurities in a clopidogrel hydrogen sulfate and aspirin compound preparation. The compound preparation clopidogrel related substances, especially specific impurities A and B produced by the compound preparation are determined by using a high performance liquid chromatography method. Stearyl bonded silica gel is used as a chromatographic column supporter, a mobile phase A is a mixed solvent of an organic solvent and ion pair buffer salt (pH 2.0-5.0), a mobile phase B is a mixed solvent of methanol and acetonitrile, elution is carried out according to a gradient condition, and texture analysis of specific impurities is carried out by using LC/MS/MS. The method has the advantages of high detection sensitivity and good precision, and high specialization for specific impurities in the clopidogrel hydrogen sulfate and aspirin compound preparation; and the method is effective for strict control of quality of the kind of compound preparation.