The invention relates to a ball screw performance testing testbed based on motor servo loading. Rolling guide rails are arranged on a bed body, a movable pair is formed by the rolling guide rails and guide rail sliding blocks, the guide rail sliding blocks are fixedly connected with a workbench, a load ball screw pair is arranged in a middle groove in the bed body, a load nut seat is fixedly connected with the workbench, linear motor permanent magnet guide rails are arranged in outer inner grooves symmetrically formed in the bed body, a movable pair is formed by the linear motor permanent magnet guide rails and linear motor sliding blocks, and the linear motor sliding blocks are fixedly connected with the workbench. The ball screw performance testing testbed can simulate static or dynamic loads through a rotary servo motor or a linear servo motor, meanwhile, the locating precision, repeated locating precision, reverse errors, temperature rise and friction torque of the load ball screw pair are examined, the feasibility of the ball screw performance testing testbed in practical work is verified, the testbed has the advantages of being flexible in loading mode, high in loading precision and stable in loading process, and load lead screws of different lengths and the identical specification can be used for tests on the same performance testbed.