Abstract - In this paper, a new trajectory planning method, the Robust Double-Space Multi-Tension Spline Method (RDSMTS), is proposed to ensure the smooth task space and joint space trajectory generation, which can guarantee the trajectory of the endpoints of the redundant robot passing through the desired knot points in the task space with time-efficient conversion only solving the specified inverse kinematics solutions. Moreover, the core algorithm of the RDSMTS method, the modified tension spline method (MTS), allows the RDSMTS method to shape all the segments of the trajectory independently by adjusting the tension factor for each segment, which leads the multi-tension trajectories to satisfy the constraints on displacements, velocities, accelerations, and jerks. The RDSMTS method can also achieve the joint limit avoidance and the singularity avoidance at the same time. The simulation results demonstrate the time-efficient and smooth performance of the proposed method.