Abstract: The pulsed-jet orderly seeding method for unmanned aerial vehicles (UAVs) utilizes a seeding pump to pressurize the seed–liquid mixture (liquid and germinated seeds), increasing the ejection velocity of rice seeds to reduce the influence of rotor airflow on seed falling trajectories, thereby achieving orderly row-and-hole seeding. Traditional seeding pumps cannot meet the requirements of pulsed-jet orderly seeding in terms of flow rate, seed damage rate, solid passing rate, and discharge pressure. To select the optimal pump configuration, comparative experiments were conducted on three types of seeding pumps: an axial flow pump, a helical impeller pump, and a semi-open impeller pump. Flow rate, seed damage rate, solid passing rate, and discharge pressure were used as evaluation indicators, with weights determined by the Analytic Hierarchy Process (AHP) at 16.76%, 23.11%, 48.41%, and 11.72%, respectively. The experimental data were also normalized for dimensionless comparison. Comparative test results show that flow rate, material passing rate and ejection pressure follow the order: semi-open impeller pump > axial flow pump > spiral impeller pump, while seed damage rate follows the order: spiral impeller pump < semi-open impeller pump < axial flow pump. The comprehensive evaluation index values of the axial flow pump, spiral impeller pump and semi-open impeller pump are 0.464, 0.231 and 0.985, respectively, demonstrating that the semi-open impeller pump exhibited superior seeding performance. Consequently, the semi-open impeller pump was selected as the seeding pump configuration for the UAV pulsed-jet rice orderly seeding system, providing a foundation for subsequent structural optimization and field prototype testing. To further optimize the structural parameters of the semi-open impeller pump, a CFD model was established, with the area-weighted average pressures at the pump inlet and outlet and impeller torque monitored. Hydraulic efficiency was used as the evaluation metric. Single-factor simulation experiments were conducted to investigate the effects of key impeller parameters: number of blades, impeller diameter, and blade width. The results showed that the effect of the number of blades on hydraulic efficiency exhibited a distinct nonlinear characteristic, increasing first and then decreasing as the number of blades increased. Hydraulic efficiency generally increased with increasing impeller diameter and blade width, indicating that all three parameters significantly influenced pump hydraulic efficiency. Maximum hydraulic efficiencies of 47.7%, 48.1%, and 52.5% were achieved when the number of blades was 5, the impeller diameter was 76 mm, and the blade width was 22 mm, respectively. To further investigate the interaction effects of impeller structural parameters on pump performance, a three-factor, three-level Box–Behnken experimental design was conducted, with flow rate and seed damage rate as evaluation indicators. The results indicated that the number of blades, impeller diameter, blade width, and the interaction between the number of blades and blade width had significant effects on both flow rate and seed damage rate. The significance of each parameter’s effect on flow rate and seed damage rate was ranked as: number of blades > impeller diameter > blade width. Multivariate regression analysis was performed to establish mathematical models for flow rate and seed damage rate. Based on the optimization objectives of maximum flow rate and seed damage rate below 0.8%, the optimal parameter combination was determined to be 4 blades, an impeller diameter of 76 mm, and a blade width of 22 mm. A prototype semi-open impeller pump with the optimized parameters was manufactured, and field verification experiments were conducted at the La Pu experimental site in Zengcheng District, Guangzhou. The results showed that the average coefficient of variation of inter-hole spacing was 13.2%, the mean standard deviation of seed hole center offset distance was 2.0 cm, and the rice yield is 6731.03 kg/hm², demonstrating that the UAV pulsed-jet rice orderly seeding system can achieve orderly row-and-hole planting and confirming the feasibility of the seeding pump for field operations.