Abstract: In order to achieve the intra-row precision mechanical weeding, an intra-row weed mechanical control device was designed based on the trochoid motion of the weeding claw tooth. The principles of weeding and crop plants avoiding were studied. And the corresponding mathematical model of the intra-row weed mechanical control device was established. The trochoid motion parameters for weed control were analyzed. The experiment of avoiding crop plants damage for the intra-row weed mechanical control device was tested on the experimental platform. Result showed that the time for switching from weeding state to crop plant avoiding state and for switching back was able to meet the switching requirement. Damaging crop plants in indoor tests was less than 8%.The intra-row weed mechanical control device was able to meet the intra-row weeding requirement for crops with a plant spacing of 20cm and larger, and ensure available weeding claw tooth for each intra-row area. The forward speed of weeding device did not affect the number of entering the intra-row region, but the increasing of forward speed would cause an increase injury rate of seedlings. The number of the claw tooth entering the intra-row area was not relevant with the uniformity of the crop plant spacing, but the crop plant spacing. This study provides a basis for precision control of intra-row mechanical weed control device.