Abstract: For studying the impact of air-impingement rotary drying structural parameters (nozzle diameter, nozzle height and nozzle angle) and process parameters (air temperature, wind speed and rotor speed) changes in the drying rate and germination rate of herbage seeds, air-impingement rotary drying technology was applied to Elymus dahuricus seeds. A predicted model of the average drying rate was established through the application of Design-Expert 7.0 software to optimize the experimental design. Experimental results showed that air-impingement rotary drying technology was better for Elymus dahuricus seeds drying and the drying results reached national first-class seed quality standard. Within the experimental conditions, the effects of air temperature, wind speed, the interaction of air temperature and nozzle angle, the interaction of wind speed and rotary speed on the average drying rate were significant and the size of the order was air temperature > wind speed > the interaction of wind speed and rotary speed > the interaction of air temperature and nozzle angle. The effects of all factors and their two-factor interactions on germination rate were not significant. This research can provide technical reference for applying the air-impingement rotary drying technology in Elymus dahuricus seeds drying.