Panax notoginseng is one of rare medicinal herbs in China, and it is mainly grown in Yunnan Province. Market demand of Panax notoginseng is very large, and hence, until December 2014, the planting area of Panax notoginseng has reached 40000hm2. However, there is no precision seeding device suitable for Panax notoginseng. Seedfilling performance is the key factor that influences the properties of metering device. In order to improve the seedfilling performance of pneumatic cylinder seedmetering device, Yunnan Wenshan notoginseng seeds were adopted as sowing objects, the method of coupling DEM-CFD was used as research technique, meanwhile, variance yields of average normal stress and height of supplying seeds were considered as the optimizing targets. Through single factor experiment, the blowing wind pressure, vibration frequency and vibration angle were numerically simulated. It can be found that the experimental phenomenon and effect were in consistent with the simulation ones. Results showed that the blowing wind pressure can break the original steady state, thus reduce seeds transient normal stress which lower seeds internal friction; vibration frequency increases variance yields of average normal stress of seeds, hence disturbance of seeds was enhanced; and adequate vertical oscillation can effectively improve height of supplying seeds. Reducing internal friction, enhancing disturbance, improving height of supplying seeds can effectively improve the seed filling performance. To find the best parameter combination, this paper used three factors and five levels orthogonal experimental method to test the metering performance, afterwards, the results of the test were optimized and verified. Results showed that at the vibration frequency of 85Hz, blowing wind pressure of 3kPa, vertical oscillation of 45°, experimental index is the best. Test indicators, including eligible index, missing index, multiple index can reach up to 93.02, 1.42 and 5.56, respectively.