Abstract: The influence of heating power, flux, bath ratio and standard addition method on the oxygen content determination in Nb-Si powder alloy by pulseheating-infrared absorption spectrometry was studied. The results show that when nickel is used as flux, the heating power is 5 kW and the standard addition method is used, the matrix interference can be eliminated, and the determination precision is higher. The relative standard deviation is1.27% and the recovery rate is between98.29% and 103.5%.The oxygen content in Nb-Si alloy can be accurately determined by this method, which can be used to measure the oxygen content of other similar alloys.