Abstract:6-DOF hydraulic manipulator has higher load ratio,but due to the response delay of hydraulic joints,the trajectory of the end effector of the manipulator would deviate.Therefore,a trajectory correction algorithm based on cubic B-spline function was proposed.The improved D-H parameter method was used to calibrate the spatial pose coordinates of the joint of the hydraulic manipulator,and the cubic B-spline function was constructed.According to the distribution of the current node vector in the B-spline curve,the relevant teaching points and control points were determined,and the serial values of the node vector changing with time were obtained;the segmented B-spline was interpolated to effectively correct the trajectory deviation of the hydraulic manipulator.The results show that by using the proposed algorithm,the local deviation of the trajectory from three axes can be controlled ,so the torque error,angular velocity error and acceleration error of the hydraulic joint can be controlled in a lower range.