Abstract: In order to improve the utilization of the planter to sow rape and wheat, based on the physical and mechanical properties of rape and wheat, a rape/wheat precision seed-metering device was designed and the main structural parameters of the seeding wheel, seed protection sheet, air chamber and other key components were determined. The dynamic process of seed filling, seed cleaning and seed unloading was analyzed, and the results showed that the limit seed-filling velocity was less than 0.18 m/s and 0.13 m/s ,the seed protecting angles were 0.175 - 0.24 and 0.201 -0.230 , and the air pressure was more than 342Pa and 458Pa for rape and wheat respectively. The bench test results of the precision seed-metering device indicated that the rape/wheat precision seed-metering device could satisfy the agronomic requirements for seeding of rape and wheat.