In order to meet the requirements of precision planting, pickup finger precision seed metering device was designed, which can perform operations of seed clamping, seed vibration cleaning and seed flexible guiding. The optimal designs of structural parameters in key components, such as the pickup finger, the vibration cleaning area, and the zero speed guiding belt, were conducted based on the analysis of working principle. To improve the working performance of the metering device and obtain the best operation parameters, the quadratic general rotary unitized design was carried out with the rotational speed of seed meter and the wire diameter of spring as the experiment factors and the seeding qualified index, the relaying seed qualified index and the missing seed qualified index as the experimental indexes. Based on experimental data, a mathematical model was built by using the Design-Expert 6.0.10 software, the experimental factors were optimized, and the best combination was achieved. Test results showed that when the spring’s wire diameter was 0.77mm and the rotational speeds were less than 19.2r/min, the seeding qualified index was 86.90%, the relaying seed qualified index was 9.62%, the missing seed qualified index was 3.51%, the improved metering device exceeded the original one by 13.5% in terms of the seeding qualified index, the damage rate of corn seed was 0.4%. On this basis, metering adaptability test was carried out which proved that the pickup finger seed precision metering device had good adaptability to corn of big flat dent, which met the requirements of precision seed sowing.