Abstract: To meet the requirements of mechanical intra-row weeding for maize, an intelligent intra-row weeding device was designed based on vertical rotating mechanism. The overall structure of the weeding device and the principle of avoiding crops were elaborated, and the key components of the weeding device were designed by theoretical analysis and EDEM simulation. Taking the working speed, the angle of disc weeding knife and the depth of weeding knife into soil as test factors, the orthogonal test was carried out based on the evaluation indices of weeding rate and injury rate. The results show that the decreasing effecting sequence of various factors on the index is the working speed, the depth of weeding knife into soil and the angle of disc weeding knife. The optimal level combination is obtained with the working speed of 0.5 m·s^-1, the depth of weeding knife into soil of 50 mm and the angle of weeding blade of 60°. At the optimal level combination, the field weeding test shows that the weeding rate and injury rate are 89.57% and 4.54%, respectively.