In order to solve that the large energy consumption and unstable sowing-performance of air-suction cylindrical, orthogonal test and regression analysis were applied to research the relative pressure and suction-hole velocity that influenced the sowing-performance mainly. Variance analysis of the experiment results defined the influencing regularity and the optimization of the factors. Experimental results indicated that the sowing-performance became worse quickly with the increasing of suction-hole velocity, but became better with the increasing of relative pressure. The optimization of the two factors was the suction-hole velocity of 0.38m/s and the relative pressure of -4.5kPa. Under such working conditions, the single seed index was 9867%, the synthetical rate of seed was 99.00%, the multiples index was 0.67%, and the miss index was 0.67%, so the seed-metering device could satisfy the demand for precision seeding. 