Abstract: A near-infrared (NIR) quality monitoring method used in column chromatography for extracting conjugated estrogens (CEs) from pregnant mare urine (PMU), that includes steps of: collecting an eluate obtained from column chromatography of a PMU stock solution as a to-be-tested sample; subjecting the to-be-tested sample to near-infrared spectroscopy (NIRS) to obtain raw spectral data, eliminating abnormal spectral values from the raw spectral data by a Mahalanobis distance method based on L1-PCA, and importing spectral data obtained after the abnormal spectral values are eliminated into a correction model to obtain a CE content in the to-be-tested sample; the correction model is a linear equation illustrating a relationship between true values and measured values, and the measured values refer to the NIR spectral data obtained after the abnormal spectral values are eliminated; and the CEs comprise one or more of sodium 17?-dihydroequilin sulfate, sodium equilin sulfate, and sodium estrone sulfate.