L、a、b色差ΔE仅为5.95。An air-impingement rotary dryer was designed, with a high coefficient of heat transfer, uniform heating of materials, energy conservation, high-volume loading compared to conventional rotary dryer. Some special structural design was used in thermal insulation, recycling of hot air, and dehumidification. The technical and structural parameters of this dryer such as hot air temperature, relative humidity, wind speed, rotary speed, branch nozzle diameter, height and angle, can be adjusted according to different materials properties and products requirement. Herbage seeds (Elymus dahuricus) and carrot cubes were adopted to test the performance of air-impingement rotary dryer. The results of drying can reach national first-class seed quality standard for Elymus dahuricus, and the value of L, a, b color difference, ΔE, between rehydration and raw materials of carrots was only 5.95. 