Microwave Digestion-Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry (ICP-MS/MS) was used to determine sulfur in crop samples, and a high sensitivity sulfur detection method in crop samples was provided. The measurement mode, interference elimination effect, linear range, detection limit and accuracy of the method were tested. The results show that the MS/MS oxygen mode can effectively eliminate the mass spectrum interference of sulfur, the method has high sensitivity, the detection limit of the method reaches 1.8 µg/g, and the sample with sulfur content below 2% can be directly analyzed by the method. The method was verified by national standard material, and the measured values were within the range of nominal value. It can be used as a new detection method for sulfur element analysis in crop samples.