Robotic milling has become another important means of advanced manufacturing technology. It has better manufacturing flexibility than machine tooling. However, the issue of low accuracy in robot machining represents a significant obstacle to the advancement of robot milling technology. Compensation of robot errors by correcting the robot joint angles can effectively improve the accuracy of robotic milling. However, changes in the angle of specific joints can lead to larger regeneration errors reducing the compensation effect. To address the above issues, a distributed compensation method for robot processing errors based on error sensitivity is proposed in this paper. The contribution of each joint to the six directions pose errors is obtained through errors sensitivity The contribution of each joint to the six directions pose errors is obtained through errors sensitivity analysis. The error compensation in the joint space is performed on some of the joints with low contribution, and the remaining part of the errors is compensated on the workpiece platform. This reduces the regeneration error and improves the compensation effect. The mean processing errors of the machined workpiece is 0.225mm, which is 19.38% lower than the conventional compensation method, as verified by the milling experiment.