Drilling and riveting robots are widely used in aviation thin-walled parts processing and assembly.When the end is equipped with a heavy-duty actuator for drilling and riveting operations,due to the influence of its own gravity and lateral cutting force,it will lead to end deformation and poor processing quality,and the weak rigidity of industrial robots limits its development in the field of precision machining.Taking the automatic drilling and riveting system of industrial robot as the research object,the kinematic model was established;the appropriate test was selected for joint stiffness identification;the joint stiffness performance index was defined on the basis of the stiffness model;the particle swarm optimization algorithm was used to find the maximum stiffness pose of the industrial robot during operation,and the joint angle parameters of the posture were determined.By selecting the appropriate processing position,the rigidity performance of the industrial robot is improved,the quality of hole processing is guaranteed,the production efficiency is improved,and dangerous accidents can also be avoided.Through the above research,the robot working posture with the optimal stiffness under drilling and riveting conditions can be obtained,and the feasibility and effectiveness of the attitude optimization method are verified in hypothetical experiments.