Abstract: Aiming at problems of high cleaning loss rate and high grain impurity content in process of harvest cleaning of mung bean, a double-inclined air screen cleaning device for mung bean was developed．Fluid-structure coupling simulation was used to simulate cleaning process of mung bean, and orthogonal test was carried out．At the same time, quadratic regression equation analysis and response surface analysis were used to explore influence of grain impurity content and cleaning loss rate．Experimental results showed that optimal parameter combination was fan wind speed of 5.7 m/s, cleaning screen vibration frequency of 4.71 Hz, upper screen lateral amplitude of 7.99 mm, lower screen surface inclination angle of 0.68 °．Under these conditions, impurity content of seeds was 2.12%, and cleaning loss rate was 2.51%, which met performance index requirements．The physical model could be used for later field experiments．