This standard specifies methods for the determination of mg content in molybdenum powder, molybdenum strips, molybdenum trioxide and ammonium molybdate by flame atomic absorption spectroscopy (AAS), applicable to the determination range of 0.0002% to 0.010%. Standard addition method for samples in muriatic acid medium by hydrogen peroxide analysis, Absorbance measurement of mg using air-acetylene Flame Atomic Absorption Spectrometer (FAAS). This standard provides reliable technical support for the analysis of mg content in molybdenum materials, and is suitable for quality control and testing in related fields.