Because of the accumulated temperature which results in two cultivations of crops in a year in the north of Huang-Huai-Hai is not enough to affect wheat tillering, people are accustomed to sowing wheat in large quantities. This sowing method not only causes wastes of water, fertilizer and other resources, but also affects the whole growth and yield of the whole wheat population due to its poor uniformity of sowing. The mechanization of wheat planting in China has been popularized, most areas use mechanical seeders for sowing, and the air suction type wheat planters have not been widely used. Compared with the mechanical seed metering device, the pneumatic seed metering device has the advantages of good applicability, good seeding uniformity, etc., therefore, the main purpose was to design a wheat air suction planter that can achieve single grain precision sowing well. The circular tube cone slot type wheat air suction seeder was designed. Through the analysis and research of several generations of prototypes developed by Professor Zhang Jinguo’s team of Hebei Agricultural University since 2008, it can be known that the gap structure used in wheat air suction seeder can improve the uniformity of filling and seeding. In view of the problems existing in previous generations of round tube slot wheat seeding machine and the problem that excess seeds were easily accumulated around the gap, a new type of pipe cone slot type wheat suction and metering device was designed to realize precision seeding, reduce the amount of sowing, and improve the uniformity of seeding effect. The structure and working principle of wheat seed suction and metering device with cone surface were introduced, and the main parameters were determined. According to the research results of previous generations of sample machines, the main parameters affecting the seed arrangement performance of the circular tube cone surface slot wheat air suction and seed ejector were determined, which were gap width, cone surface angle and negative pressure respectively. The optimum parameters and conditions for the operation of wheat seed suction and metering apparatus with taper surface were determined by multi-group single factor test and orthogonal test. When the cone angle was 90 degrees, the gap width was 0.7mm, negative pressure was 4.0kPa, and the adsorption rate was 85.89%. By bench contrast test, the result showed that when the gap surface had serrated spacing, and the length was 1.5 times of seed, the adsorption rate could be increased to 88.82%. The negative pressure value of the seed-device was obtained by calculation, the negative pressure range for successful adsorption of seeds was 8~13.3kPa. It was also calculated that the required fan power should be greater than 1.47kW. Field trials showed that the average variation coefficient of sowing uniformity of wheat seeder with suction and metering device with cone surface of circular tube was 31.20%, less than 45%, which met the national standard.