Abstract: Objective:To study the rapid determination of lactic acid content in base liquor by Modern Near Infrared Spectroscopy.Methods:High performance liquid chromatography was used to determine the chemical value of lactic acid in base liquor, which was combined with near infrared transmission spectrum, and established the quantitative detection model of lactic acid in base liquor. Results:The best spectral pretreatment method was the first derivative + multivariate scatter correction (MSC), the optimal band spectrum was 6102~5450 cm^-1. Through optimized and validated the model, the determination coefficient (R²) between the chemical value and the near infrared predicted value was 0.9771; the correction standard deviation (RMSECV) was 0.1825; the determinant coefficient of the validation set (R²) was 0.9808, the prediction standard deviation (RMSEP) was 0.1475.Conclusion:Near infrared detection method was fast and effective, the model had good prediction effect, and the precision and stability of the model was good, providing guidance for the determination of lactic acid content in liquor industry.