Abstract: In order to solve the problem of difficult cutting of ridge grass in ridging cultivation orchard, a cutting mechanism for avoiding obstacles of ridge grass was designed. Through kinematic simulation analysis, the length of each connecting rod is optimized with pressure angle and acceleration as the main optimization indexes, and the selection of pneumatic hydraulic rod is determined; the motion parameters of obstacle avoidance cutting mechanism and key motion nodes are analyzed. It is concluded that the trajectory of obstacle avoidance cutting mechanism is an outer arc, the maximum angular velocity is 22.5°/s, the maximum acceleration is 45 °/s~2, the maximum obstacle avoidance displacement in x-axis is 550mm, and the maximum obstacle avoidance displacement in-y-axis is-250mm.The field test results showed that the average height of cutting stubble was 63.36 mm, the average stability coefficient of cutting stubble was 90.30%, greater than 90%, the average miss cutting rate was 2.18%, less than 3%, and the obstacle avoidance passing rate of fruit trees was 100%, which met the gardening requirements of obstacle avoidance mowing between plants on the ridge.