According to magnetic precision seed-meter theory, a new type of magnetic cylinder-seeder was designed, the primary factors which influenced the performance of the seeder were analyzed, and the plug-seeding test by Uniform Design was conducted. Based on the experimental results, the regressive equations were established among the electric current value, coil turn, cylinder rotational speed and the percentage of single seed, and its primary working parameters were optimized. The experimental results for cole seed indicated that the single-seeding rate was 94.3%, leakage-seeding rate was 0, and the seeding efficiency can reach 333 sets per hour under the optimized working parameters, so the seed-metering device can satisfy the demand for precision seeding.