In order to solve the problem that the unreasonable design of the clearing mechanism of the air-suction maize seed-metering device, which causes the missing-clearing and over-clearing and reduces the performance of the air-suction maize seed-metering device. A method of using a double-sided seed cleaning mechanism for seed cleaning was presented and a double-sided seed cleaning mechanism was designed. By analyzing the process of seed clearing, the reason of reabsorption was clarified, the movement mechanism of the process of seed clearing was clarified, and the mathematical model of the upper side of the process of seed clearing was established. The shape parameters of the upper seed cleaning mechanism, the interval angle of the upper and lower seed cleaning devices and the lower seed cleaning intensity were determined. The whole factor test was carried out with the first level clear arc top radius, the second level clear arc top radius and the working speed as the main factors. In addition, significant analysis on the test results was performed to determine the regression equation of factors and indicators. Meanwhile, missing-clearing rate and over-clearing rate were used as test indexes. The results showed that the better clearing intensity was determined as the first level clear arc top radius was 80.70mm, and the second level clear arc top radius was 81.42mm. The verification test results showed that under the combination of better cleaning intensity, when the rotational speed was 26.67~37.33r/min, the missing-clearing rate was less than or equal to 1.10%, and the over-cleaning rate was less than or equal to 1.03%, which were consistent with the theoretical optimization results. The comparison test showed that the missing-clearing rate improved at all test working speed. When the rotational speed was 26.67r/min, compared with single-side seed cleaning mechanism, the missing-clearing rate was reduced by 6.70 percentage points, the over-cleaning rate was basically unchanged，the qualified rate was increased by 7.04 percentage points. When the rotational speed was 32.00r/min, compared with single-side seed cleaning mechanism, the missing-clearing rate was reduced by 4.63 percentage points, the over-cleaning rate was basically unchanged，the qualified rate was increased by 5.07 percentage points. When the rotational speed was 37.33r/min, compared with single-side seed cleaning mechanism, the missing-clearing rate was reduced by 7.41 percentage points, the over-cleaning rate was increased by 0.24 percentage points，and the qualified rate was increased by 7.26 percentage points. The double-sided seed cleaning mechanism can effectively reduce the missing-clearing rate and improve the over-cleaning rate at high speed.