High-speed mechanised peanut sowing often suffers from missed and multiple seeding because seed pickup and release become unstable at elevated disc speeds. To meet agronomic requirements in Henan Province, an air-suction high-speed precision seed discharger was developed, incorporating a dual-orifice vacuum chamber with adaptive negative-pressure regulation to stabilise single-seed adsorption and enable low-impact delivery. A seed–metering-disc interaction model and kinematic analysis were established to guide the structural design and operating window. Based on force analysis of the filling and carrying stages, key parameters were determined: a 210-mm metering disc with 1.6-mm thickness, 25 suction holes, a hole diameter of approximately 7 mm, and a recommended chamber vacuum of 4–6 kPa. A three-factor, three-level combined experiment was conducted using planter forward speed, chamber negative pressure, and suction-hole diameter as factors, with qualified singulation rate, miss-seeding rate, and multiple-seeding rate as responses. Regression models were fitted and optimised, yielding an optimum at 8.617 km·h⁻¹ forward speed, 5.816 kPa chamber vacuum, and 7.02 mm suction-hole diameter. Under these conditions, the qualified seed-discharge rate reached 94.86%, while the miss-seeding and multiple-seeding rates were 3.49% and 1.65%, respectively, satisfying the requirements for high-speed precision peanut seeding.
