The chemical determination method of quality traits is cumbersome, destructive and time-consuming. The spectral determination method has the advantages of high efficiency, speed and low cost, but the accuracy is affected by different instruments and models. In order to establish and optimize the model for rapid determination of crude protein (CP), ether extract (EE), acidic detergent fiber (ADF) and neutral detergent fiber (NDF) using near-infrared diffuse reflectance spectra of alfalfa samples, and better determine the quality traits of alfalfa. A total of 147 samples of 25 alfalfa materialswere selected. The scanning spectral values of the spectral range of 4 000～10 000 cm-1 are obtained by scanning with Fourier transform near-infrared spectroscopy (NIRS). The software TQ Analyst V9 adopts partial least squares (PLS), and OPUS 7.0 adopts the quantitative 2 methods to establish and optimize the quantitative model and further carry out cross-validation and external test to evaluate the effect of the model. The results showed that the models for determining CP content were also through two software. Two modeling coefficient of determination (R2cal) were 0.999 and 0.984 8, the root mean square error (RMSECV) of cross-validation was 2.121 and 0.471, respectively. The coefficient of determination (R2) of external validation is greater than 0.97, and the ratio of standard deviation to SEP (RPD) was greater than 6.0. The model established by TQ analyst V9 was better for EE with R2cal of 0.999 7, RMSECV of 1.502, R2 of external verification of 0.929 3 and RPD value of 3.89. The models established by OPUS 7.0 were better for ADF and NDF with R2cal of 0.944 1 and 0.978 8, RMSECV of 1.040 and 0.514, R2 of external verification of 0.914 5 and 0.911 8, and RPD of 3.66 and 3.43, respectively. The modeling results of four quality traits showed that the models of TQ Analyst V9 are more accurate for CP and EE with relatively simple molecules structure, while the models of OPUS 7.0 are more accurate for ADF and NDF with relatively complex molecular structures.