A modular Fourier Transform Infrared Spectroscopy （FTIR）characterization platform was designed and set up.The analytical method for determining hydrogen trace impurities in proton exchange membrane fuel cell vehicles (FCV) has been developed.After reducing the purity requirement of blank gas,specific target contaminants, including HCOOH，CO，CO2，NH3，H2O，CH4，C2H4，C2H6，C3H8，HCHO still could be rapidly determined simultaneously without any pre-process with high accuracy and reproducibility.The detection limits of the nine impurities still reach the ASTM D7653-18 reference value,and their quantitative limits are also lower than the corresponding limits of ISO 14687：2019.The method meets applicability verification rules in ISO 21087：2019. According to the requirements of hydrogen trace impurities in different scenarios,the modular FTIR system can be organically combined with good practicability,and the hydrogen concentration can be reduced to 100μmol·mol-1 after treatment, which meets thesafety and environmental protection requirements.It is consistent with the measured values of other reference methods in the laboratory.It will be gradually developed into an on-line method for different industrial scenarios.This is significant for the establishment of fuel-grade hydrogen quality systems,the application of purification technology and the development of new materials for fuel cell catalysts.