Abstract: In the treatment process of proton radiation therapy, the patient needs to be positioned and immobilized before being moved into the treatment position. In this study, the patient was primarily positioned using the 6R robotic treatment couch as the patient support system (PSS). A simplified three-dimensional model of the treatment room was developed based on the relative motion within the treatment room. The forward and inverse kinematics of the 6R robotic treatment couch were analyzed using an improved Denavit-Hartenberg (D-H) representation. A collision interference model was created based on the actual treatment process. The motion path of the treatment couch was planned and simulated in MATLAB using an improved artificial potential field method for obstacle avoidance. The results indicate that the robotic treatment couch can smoothly navigate around obstacles to reach the target point, satisfying the positioning requirements for proton therapy.