The invention discloses a barrier escaping motion planning method based on an impact degree. The method comprises the steps of 1) designing barrier escaping motion performance indices based on the impact degree so that the designed motion performance indices are subject to a Jacobian matrix equation based on the impact degree, a barrier escaping inequation based on the impact degree, joint angle limitation, joint speed limitation, joint acceleration limitation and joint impact degree limitation, and generating a quadratic form optimization redundancy analysis scheme, 2) transforming the quadratic form optimization redundancy analysis scheme generated in the step 1) into a secondary planning problem, 3) solving the secondary planning problem in the step 2) by use of a secondary planning solver, and 4) transferring the solution result of the step 3) to a lower computer controller to drive a mechanical arm to move. According to the barrier escaping motion planning method, the barrier escaping motion performance indices based on the impact degree are designed, the mechanical arm is controlled to escape a barrier at an impact degree layer, and meanwhile, the mechanical arm is capable of completing a given tail end task.