To address the issues of high seed damage rate and low seeding uniformity of mechanical wheat seed metering devices in the arid regions of northwestern China, this study designed a flexible impeller-type precision wheat seed metering device. To the seed damage due to high pressure when in a seed jamming state, a flexible tooth made of polyurethane material was designed. It absorbs the pressure on the seeds by utilizing the elastic deformation of the tooth, thereby achieving the purpose of seed protection. This study also designed a seed protecting hook. By utilizing the coordination between the seed-protecting hook and flexible teeth, the orderliness of seed flow is improved, thereby enhancing seeding uniformity. The DEM-MBD coupled simulation was used to simulate the seeding process. From a microscopic perspective, this study analyzed the working principle of flexible teeth, their stress distribution, and the main cause of seed damage-excessive compressive force. With this compressive force and seeding rate uniformity as indicators, single-factor experiment and optimization experiment designed based on Design Expert software were conducted. The results indicate that the seedmetering device achieves optimal performance with the following parameters: seed-protecting hook angle of 28.80 degrees, 1.94 mm clearance between the hook and flexible teeth, and flexible impeller speed of 4.09 rad & sdot;s- 1. The bench test results indicate a seed breakage rate of 0.188 %, while the seeding volume coefficient of variation (CV) was measured at 2.66 %. Field trial data reveals a seeding volume coefficient of variation of 3.38 %. These evaluation criteria meet the standards.