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Aiming at the problems of inadequate use of air pressure for air suction type metering device, friction between seed plate rotation and rubber pad, and poor uniformity of hole sowing, airflow field of rice seed metering device embedded with rotating air chamber was designed by the absorption principle. The working principle of each stage of seed metering device was introduced, and the parameters and structure of the key components were designed. Based on the basic governing equation of fluid, the negative pressure cavity was simulated by ANSYS software. The numerical simulation was carried out with the influence factors of pore diameter and position distribution of suction hole. The average pressure of the cavity and the average velocity of the suction hole were the evaluation indexes. The simulation results showed that the distribution of flow field in air cavity was relatively stable, which provided a stable negative pressure environment for seed suction. The JPS-12 test-bed was applied to verify the simulation test. Taking the rotation velocity of air chamber, the negative pressure of air chamber and the height of seed filling as the influencing factors, and taking the qualified rate of rice sowing, the rate of missed sowing and the rate of re-sowing as the evaluation indexes, the experiment of quadratic rotation combination design at five levels of factors was carried out. Using Design-Expert 8.0.6 to complete variance analysis and significance test, the regression equation and the corresponding surface map were obtained, the interaction of various factors was analyzed, and the best parameters were determined. Number combination: when the rotating velocity of the air chamber was 21.61r/min, the negative pressure of the air chamber was 4.4kPa and the seed filling height was 15.7cm, the performance of the operation was 93.6% for the qualified index, 3.47% for the missed broadcast index and 2.93% for the replay index. The experimental results of bench test were in good agreement with the optimized results, which met the requirement of direct seeding of japonica rice.