Based on the requirement of complicated surface polishing from manufacturing automation, aiming at solving the complex and inefficient online teaching of robotic polishing system, this paper proposes a force-controlled polishing system and implements off-line programming on process path of blade polishing by robot through analyzing the deformation of the contact part between blade and buffing wheel. Finite element was used to analyze the contact part, and the blade polishing module was developed in the environment of robot studio combining the horizontal line cutting method and the Douglas-Peucker algorithm. Simulation was taken on the off-line module and the resulting file was input into the industrial robot to carry out experiments. The results show that this method had better experimental effect and faster processing efficiency.