In order to improve the seeding performance of the airsuction seed metering device of notill planter, the optimal operating parameters of the seed metering device were found. With the discrete element method, the dispersion degree, the force among the seeds and seed velocity in seed metering device were simulated. The best suction metering parameter ranges are as follows: the stirring wheel speed is 14.8～18.5r/min, the vibration frequency is less than 10Hz, the amplitude selection is less than 5mm, and the capacity of seeders selection is 60%~80%. The results of metering test verification show that: the wheel speed is less than 18.5r/min, the average absorption rate is 94.7%, which is 7.1% higher than absorption rate of the seed stirring wheel speed greater than 18.5r/min. The vibration frequency is less than 10Hz and the amplitude is 2mm, the average absorption rate is 97.7%. Compared with the absorption rate of super 10Hz, the average increase of the absorption rate is 8.9%. The absorption rate is increased with the increase of the capacity of seeders. When the capacity of seeders is less than 60%, the average rate of absorption seed is only 85%; while the capacity of seeders is higher than 60%, the average rate of the absorption is 97%. Compared with the capacity of less than 60%, the average absorption rate was increased by 12 percentage points. This conclusion proves that working parameters of the simulation analysis and optimization are reliable. Therefore, the seeds of the airsuction seed metering device are in a loose absorption state in the ranges of those parameters, which could furthermore reduce collision and towing function of the seed, more conducive to the suction, and improve absorption performance.