Carrots are prone to impact damage during the root-stem separation stage, and it is easy to cause fruit damage due to the impact between the pull rod and the carrot. To reduce the damage of carrots harvested by pulling, the finite element method was used to study the critical velocity of carrot damage after the improvement of the pull rod (a rubber cushioning material with a thickness of 2mm, and inner diameter of 16mm, giving a 20 mm outside diameter, and elastic modulus of 100 MPa was wrapped outside the pull rod). The critical rotational speed of the disc driving the pull rods was solved by kinematic analysis of the pulling separation mechanism and impact velocity analysis of carrots. According to the nonuniform motion characteristics of the pull rod, a noncircular gear transmission device was designed, and a root-stem separation experiment was carried out. Because rubber cushioning material affected the success rate of separation and active disc rotational speed affected the damage rate of separation, the experimental factors were pull rod surface with or without rubber cushioning material and active disc rotational speed. Through the separation experiment, it was found that when the rubber cushioning material was used in the pull rod, and the conveyor belt velocity was 1 m•s-1 and the input rotational speed of the disc driving the pull rods was 180 rpm, the separation success rate of carrot was 90% and the damage rate was 5%.