Abstract: Aiming at the problems of carrot harvester such as high carrot damage rate and poor root-stem separation effect, a pull-type carrot root-stem separation test bench driven by servo motor was designed. The Box-Behnken experimental design with three factors and three levels was performed, parameters such as the acceleration of pull-rod, rotation speed of active disc and Angle between pull-rod and conveyor belt were selected as independent variables, and the success rate and damage rate of carrot root and stem separation were taken as response values. Furthermore, the mathematical model was established, and the main reasons that affected carrot root-stem separation were analyzed as well. The results showed that the motion characteristics of pull-rod had a significant influence on the separation effect of carrot rhizomes. Meanwhile, the optimal motion parameters of carrot root-stem separation mechanism were obtained as follows: the rotation speed of pull-rod driving disk was 158 r/min, the acceleration of pull-rod was 0 m/s~2, and the included angle between pull-rod and conveyor belt was 48°. The experimental results showed that the success rate of carrot root-stem separation was 96.2% and the damage rate was 5.2% under the optimized working parameters, which could provide a reference for improving the pull-type carrot harvester.