Abstract: Precision seed-metering is one of the most crucial procedures for the high yield of maize. However, the traditional seed-metering devices have been confined to unstable operation, seed damage, seed clogging, and low versatility in recent years. In this study, a chain-scoop precise seed-metering device was designed for maize. The seed-metering device primarily consisted of housing, seed scoop, seed metering chain, sprockets, drive shaft, bearings, mounting base, and seed box. According to the physical properties of the maize seeds, the structural parameters were optimized on the chain-scoop precise seed-metering device. The key component, the seed scoop, was also designed after optimization. The seed-metering chain was selected as the 06B chain number with a K-type attachment plate. The seed scoop was designed in a "7"-shaped structure, with the length determined as 20 mm, the width as 27 mm, and the height as 12.5 mm. The seed-filling hole and the bottom groove were designed in a spherical shape with evenly distributed elliptical notches. As such, the seeds were rested obliquely within the seed scoop. The radius of the seed-filling hole was ranged from 4.5 to 6 mm, while the short diameter of the elliptical notch was 1.05 mm, and the radius of the bottom groove was 4.17 mm. The chain-scoop assembly was designed to evenly attach the seed scoops to the seed-metering chain. A seed-metering motor was operated to implement four procedures: the seed filling, clearing, protection, and delivery. A theoretical analysis was conducted on the motion states of the target seeds during the process. The key influencing factors on the seed-metering performance were identified, such as the speed of the driving sprocket, the radius of the seed-filling holes, and the inclination angle of the seed scoop. The discrete element method (DEM) with multibody dynamics (MBD) was employed to examine the operational process of the chain-scoop precise seed-metering device. The mathematical model was then established to validate the motion of maize planting. The test results demonstrated that the maize seeds successfully passed through each working area of the seed-metering device. The seeding function of the chain-scoop planter fully met the requirements of the performance. A series of bench tests was carried out on the chain-scoop precise seed-metering device. Design Expert 12.0 software was utilized to perform a three-factor, three-level, second-order orthogonal rotational experiment. The operating parameters were fine-tuned to optimize the performance. A systematic analysis was made on the effects of these parameters—such as the speed of the driving sprocket, the radius of the seed-filling hole, and the inclination angle of the seed scoop—on the seeding performance, including the qualified rate of planting hole spacing and the miss-seeding rate. Subsequently, a regression equation was established using the collected data. The optimal operating parameters were identified for the maize seed planting: a sprocket speed of 45.6 r/min, a seed-filling hole radius of 5.45 mm, and a seed scoop inclination angle of 3.42°. Furthermore, the planting test was achieved in a qualified planting hole spacing rate of 83.14% and a miss-seeding rate of 1.73%. The feasibility rate of 98.3% was predicted under the optimal combination of the parameters. The prototype of the precise seed-metering device was designed for ready installation with the chain-scoop technology. Field tests were conducted according to the optimal combination of the operating parameters after bench tests. The better performance was achieved in an average qualified planting hole spacing rate of 81.67% and an average missing rate of 1.67%, fully meeting the national standards of precise seed planting. Therefore, the chain-spoon precision seed-metering device also shared the simple seeding structure and low cost suitable for use in small corn seeders.