Abstract: In order to determine the optimal quality parameters of Astragalus membranaceus var. mongholicus and realize the precise sowing and coating pelletization of Astragalus membranaceus var. mongholicus seeds, the external morphology, clarity, 1000-grain weight and germination rate of Astragalus membranaceus var. mongholicus seeds from 16 different origins were tested. The indexes such as purity, thousand-grain weight, germination rate and water content of Astragalus membranaceus var. mongholicus seeds with different particle sizes in 3 different producing areas of Shanxi were studied, and SPSS was used to analyze the variance to find the optimal quality parameters of Astragalus membranaceus var. mongholicus seed particle size. The results showed that the three kinds of Astragalus membranaceus var. mongholicus seeds in Shanxi were divided into 4 grades of particle size. The seeds of Astragalus membranaceus var. mongholicus with a particle size of 2.3-2.5 mm were the best, the thousand-grain weight was between 6.8 870 and 6.9 450 g, the water content was between 8.43% and 9.73%, and the germination rate of the germination box was between 94.4% and 96.8%, the sandbox germination rate was between 82.4% and 91.6%, and the field seedling rate was between 46.0% and 61.5%.