Abstract:A rice-wheat universal pneumatic roller precision seed metering device was designed for the rice-wheat rotation area in the middle and lower reaches of the Yangtze River.The roller adopted the split-section structure,which can be disassembled and assembled from the radial direction,simplifying the disassembly and assembly process,and reducing the impact on the sealing room. Huanghuazhan rice and Zhengmai 9023 were used to conduct a single factor test to investigate the effects of socket type,rotational speed of drum,vacuum degree and height of seed in hopper on the seeding performance of the metering device evaluated by indexes including qualified rate,miss-seeding rate and reseeding rate. The working parameters was optimized and validated by orthogonal experiment. The results showed that the cone socket was suitable for rice and the ellipse socket was suitable for wheat. The effect of the height of seed in hopper on the performance was slight,while the rotational speed of the drum and the vacuum degree significantly affected the performance. The optimal working parameter combination of rice obtained from the analysis was drum speed 17 r/min,suction negative pressure 4.6 kPa,and seed layer height 40 mm; The optimal working parameter combination of wheat was drum speed 21 r/min,seed suction negative pressure 4.2 kPa,and seed layer height 40 mm. Under this parameter combination,the qualified rate of seeding and miss-seeding rate of rice were 86.81% and 4.61%,respectively; and that of wheat were 81.84% and 7.83 %,respectively. It is consistent with the optimized prediction results,and each index meets the basic requirements for seeding.