The invention relates to the field of food safety detection, in particular to a method for measuring the residual quantity of streptomycin and dihydrostreptomycin in vegetable food. The method for determining the residual quantity of streptomycin and bistreptomycin in the vegetable food by LC-MS/MS is established; the method comprises the following steps: extracting streptomycin and dihydrostreptomycin in a vegetable food sample by using an extracting solution, centrifuging, purifying a to-be-detected object from supernate by using a method of combining dispersive solid-phase extraction primary purification and serially-connected double-column solid-phase extraction purification, blow-drying by using nitrogen, and dissolving residues for LC-MS/MS determination. The method is high in practicability, good in operability and suitable for detection of streptomycin and dihydrostreptomycin.