In the present study, near infrared reflectance spectroscopy(NIRS) was used as a rapid and accurate method to determine the residual of acrylamide monomer in the product of diallyl dimethyl ammonium chloride and acrylamide. In this experiment 38 products were used which were self-prepared in the laboratory, then near infrared spectra of the product were scanned, seven bands were selected, the characteristic peaks of each band were used as the independent variables, and the absorption peak was used as the dependent variable, using partial least squares (PLS) method to establish the mathematical conversion near infrared reflectance spectroscopy (NIRS) calibration model. In the analysis of the spectrum, using wavelet analysis as the method of reducing the noise of spectrum, and with comparison of the simulated value and measured value, the measured value was determined by using UV spectrum, the external validation determination coefficient was found to be 0.99, and the distribution trend forecast was good. Statistics showed that there was no significant difference between simulated value and measured value. The results show that using the calibration model established by the data of near infrared spectroscopy to predict the residual AM monomer in PDA is of high feasibility.