The content of cellulose and lignin in the separated skin, core and leaves of corn straw were analyzed by means of combination of spectral analysis and chemical detection, and then the validity of prediction models were tested in order to realized the rapid nondestructive detection of the different parts of the components of straw. The results showed that the content of cellulose and lignin of corn straw were determined as skin, pulp and leaves sequence by the vibration strength of H group in spectral information. The cellulose model was pretreated by first order differentiation and standardization, and the lignin model was pretreated by first order differential and standard normal variables, The verification analysis of the experiment shows that the relative errors of the prediction models are less than 3% indicating a higher correlation and prediction effect. The results show that the test data online by FTIR of cellulose and lignin in the separated skin, pulp and leaves of corn straw content is reliable, It provides a new rapid nondestructive measuring method with high efficiency. © 2019, Editorial Board of Acta Energiae Solaris Sinica. All right reserved.