Abstract: To address the problem that the negative pressure seed-suction method using a straight seed guide tube causes airflow interference in the sowing area, leading to high-frequency seed loss and compromising sowing quality, this study systematically analyzed the negative pressure seed-suction process of the straight seed guide tube. A mechanical model was established for the stable adhesion of seeds in the seed release area of a pneumatic precision seeder. The study clarified the influence mechanism of the straight seed guide tube on sowing consistency. It was found that the straight seed guide tube increases the high-speed air flow suction force at the seed release point, making it more likely to induce premature seed release, thus affecting the uniformity of seed distribution.Building upon these findings, an innovative negative pressure seed-suction method utilizing a seed-suction bend tube was proposed. Theoretical research on the negative pressure seed-suction process using the seed-suction bend tube was conducted, and both the mechanical and kinematic models of the seed-suction bend tube were developed. The high-speed air flow suction force at the seed-suction bend tube’s inlet was found to be related to the seed-suction angle. Through theoretical analysis of the structural parameters of the seed-suction bend tube negative pressure seed-suction high-speed air flow seed guide device, key parameters such as the diameter of the seed-suction bend tube, seed-suction angle, and bend tube shape were determined. The diameter of the seed-suction bend tube was selected to range from 18 to 22 mm. Based on the structural dimensions of the seeding device and the seed-suction bend tube negative pressure seed-suction high-speed air flow seed guide device, the seed-suction angle was determined to be 37°, and the length of the seed-suction bend tube was set to 35 mm. The seed movement trajectory within the seed-suction bend tube negative pressure seed-suction high-speed air flow seed guide device was determined, and the shape of the bend tube was designed accordingly.A three-factor, three-level experimental design was established with working speed, pressure at seed suction inlet, and diameter of the seed-suction bend tube as the primary experimental variables. The results of the experiment indicated that when the corn seed plant spacing was 25 cm and the working speed of the seeding device was 13 km/h, the optimal combination of parameters was a pressure at seed suction inlet of 1.0 kPa and a diameter of seed-suction bend tube of 21 mm. Under these conditions, the coefficient of variation of seed release time difference was 8.12%, which met the sowing uniformity requirements for the seed-suction bend tube negative pressure seed-suction high-speed air flow seed guide device under high-speed operating conditions. Comparative experimental results demonstrated that when the working speed ranged between 12 and 16 km/h, the coefficient of variation of seed release time difference in the seed-suction bend tube negative pressure seed-suction high-speed air flow seed guide device was reduced by more than 4.6 percentage points compared to the Seed-suction straight tube negative pressure seed-suction high-speed air flow seed guide device. This indicated that the seed-suction bend tube negative pressure seed-suction high-speed air flow seed guide device was more effective in improving the temporal uniformity of the sowing process, thus significantly enhancing sowing uniformity and accuracy under high-speed operating conditions.The sowing uniformity of different corn seed varieties was found to have a coefficient of variation of seed release time difference no greater than 12.9%, indicating good sowing effectiveness and variety adaptability. The use of the seed-suction bend tube negative pressure seed-suction high-speed air flow seed guide device can effectively enhance sowing consistency. By adopting the new negative pressure seed-suction bend suction method, future sowing operations can improve working efficiency while ensuring high-quality sowing, ultimately laying the foundation for high crop yields and stable growth.