In order to improve the working performance of the air-supplied collecting and discharging system of alfalfa cut-root reseeding and fertilizer applicator, the EDEM software and Fluent software were used to co-simulate the working process of the air-carrying collector and distributing device, using the internal flow field pressure and velocity changes in the pipeline, the seed particle velocity and the force as indicators to analyze the impact of configuration parameters of the corrugated pipe and the distribution head on performance of the platoon, and its structural parameters were optimized. Taking the elbow diameter ratio, length of the fold pipe and taper angle of the distribution head as the test factors, and coefficient of variation of the consistency of each row displacement and coefficient of variation of the total displacement as the test indicators, the Box-Behnken response surface analysis simulation set and row test was carried out to obtain the optimal combination of structural parameters of the collection system. The results showed that when the bending diameter ratio was 0.96, the length of the corrugated tube was 183mm, and the taper angle was 123.4°, at this time, the coefficient of variation of the consistency of each row’s displacement was 3.06%, and the coefficient of variation of the total displacement was 3.17%. The field performance test results of the prototype showed that under different conveying efficiency conditions of the screw conveyor, the consistency coefficient of variation of the row of reed wool seeds and solid granular fertilizer and the coefficient of variation of the total discharge were less than 5%.