In response to the problems of reseeding, leakage, and poor adaptability to different types of maize seeds, a top bar clamping-type maize precision seed-metering device is designed. By controlling the opening and closing of the seed picking block through a clamping system, a clamping space is formed with the steel strip for seed picking and cleaning. The effects of torsion spring initial installation angle and torsion force on seed picking and carrying are analyzed, and a mechanical model for the seed picking process is established. To verify the operational performance of the seed-metering device, a three-factor, three-level experiment is conducted using the depth of the seed block, the initial installation angle of the torsion spring, and the speed of seed-metering device as experimental factors, and the qualification index, leakage index, and replay index as experimental indicators. The experimental results are analyzed and optimized to obtain the optimal theoretical parameters. When the depth of the seed block is 8.7mm, the torsion spring angle is 51.4°, and the seed-metering speed is 28.5r/min, the qualification index is 95.0%, the leakage index is 3.1%, and the reseeding index is 1.9%, meeting the agronomic requirements for maize planting. The results provide valuable references for designing mechanical precision seed-metering devices for maize.