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In view of the fact that the current corn grain harvester can not meet the need of large feeding quantity cleaning above 15kg/s, a kind of cleaning device with pre-cleaning function was designed. Firstly, the stress analysis of corn grains before the extruder leaved the screw conveyor and reached the pre-cleaning screen was carried out, and then the motion model of the crank linkage mechanism was simplified. Secondly, the motion state of corn grains on the sieve surface was analyzed. The impeller and volute of centrifugal fan were designed and calculated. The single factor test was used to determine the fan speed, vibration frequency and the value range of the upper screen opening. With the fan speed, vibration frequency and the opening of the upper screen as test factors, and the grain impurity content and cleaning loss rate as evaluation indexes, the three-factor and three-horizontal center combined test was designed to establish a regression model between the factors and indexes. The test results were analyzed by response surface method, and the regression model was optimized by DesignExpert 12. When the feeding amount of corn extract was 16kg/s, the optimal combination was obtained. The test results showed that the fan speed was 1202.50r/min, the vibration frequency was 5.41Hz, and the opening of the upper screen was 18mm. Under these conditions, the grain impurity content was 0.79% and the cleaning loss rate was 1.10%. The verification test showed that the speed of the fan was 1200r/min, the vibration frequency was 5Hz, and the opening of the upper screen was 18mm. At this time, the kernel impurity content was 0.82%, the cleaning loss rate was 1.14%, the relative error between the test value and the optimization value was less than 5%, and the kernel impurity content was 2.07 percentage points lower than that of the traditional double-layer reciprocating vibrating screen cleaning device. The loss rate of cleaning was reduced by 2.13 percentage points, which proved that the design was reasonable and met the national cleaning standard.