This standard describes the use of secondary ion mass spectrometry for the determination of nitrogen content in silicon single crystals, suitable for silicon single crystals with a doping concentration of less than 1 × 10 ² ± cm ³. Methods The sample was bombarded with a cesium Ion source in a high vacuum environment, and the sputtered secondary ions were separated and determined by Mass Spectrometer. The content of nitrogen in silicon single crystals was calculated by recording the intensity ratio of nitrogen-silicon composite ions to silicon main ions, combined with the relative Sensitivity Factor method. This method provides reliable technical support for high-precision nitrogen content analysis.