Usual analytical methods are complex and require rigorous experimental condition. In order to meet the demand of fire product supervisory department in rapidly detecting the quality of dry chemical, a rapid and nondestructive method was proposed to determine the moisture content in ABC dry chemical using near infrared spectroscopy of fiber diffuse reflection. The calibration models were established for determination of moisture content of ABC dry chemical by partial least squares and 47 ABC dry chemical sample spectra. Spectral data preprocessing and Spectral region selection were discussed. Correlation Coefficient of Calibration Set of the model was 0.976, root mean square of error cross validation was 0.037 1, correlation coefficient of prediction set was 0.952, and root mean square error of prediction was 0.021 6 in the predicted rang of 0.075%~0.334% for moisture content of ABC dry chemical. Using the Chisquare test method, repeatability standard deviation measurements all belonged to the same overall at a 95% confidence level. All the relative standard deviations were less than 7.0%. The near infrared spectroscopy method is used to test the moisture content of ABC dry chemical is feasible.