Abstract: An intra-row weeding mechanism was designed. To optimum the design and confirm the optimal combination of the key parameters of the mechanism which is one part of cultivators, the experimental date was processed by orthogonal test method, the effect degree of working parameters of the weeding unit on intra-row weeding rate and its injuring seedling rate was determined，through range analysis, and the best operational parameters combination was discovered. The experiment result indicated that the number of weeding tines and revolving speed of the comb disc had significantly effect on the performances of the weeding unit. According to the analysis, the best scheme was: the number of weeding tines 6, and revolving speed 180 r/min, space between the tines 50 mm, work velocity 2.3 m/s. Under such working conditions, the injury seedling rate and weeding rate were 2.74% ,87.6% respectively. The study can provide theoretical basis for the design of reliable intra-row weeding mechanism.