The invention belongs to the technical field of analysis and particularly relates to an analysis method for measuring the content of iron in mercaptopropionic acid with ICP-MS (inductively coupled plasma mass spectrometry) method. According to the method, after mercaptopropionic acid is treated with low-temperature volatilization and high-temperature calcination sample pretreatment methods, the content of iron in a sample is detected. The ICP-MS method used for measuring the content of iron in mercaptopropionic acid is high in sensitivity, wide in linear range and low in detection limit, and the results of measurement accuracy of iron in the sample and the standard recovery rate show that low-temperature volatilization and high-temperature calcination pretreatment methods can meet the requirement for measurement of the content of iron in mercaptopropionic acid.