Objective:To evaluate the feasibility of using a visual positioning system for both motion phantom and clinical quality control.Methods:A phantom experiment was conducted using the Dynamic Thorax Phantom from CIRS. Different ranges of motion were simulated to assess the discrepancies between camera-recorded positions and actual movements. Visual markers were also attached to the treatment bed and the collimator head, and their movements were simulated as part of the experiment. The experiment was repeated for three times. Discrepancies between system measurements and manual measurements were recorded and analyzed to assess the accuracy and reliability of the system.Results:In the motion phantom test, the deviation between the actual motion distance of the phantom and the system's recorded measurement was (0.18±0.07) mm. For linear motion analysis along the X, Y, and Z axes on the treatment table, the measurement errors were (0.14±0.08) mm, (0.15±0.09) mm, and (0.16±0.08) mm, respectively. Additionally, the measurement error in the rotational direction of the treatment couch was 0.18°±0.09°. For the rotational direction of the collimator head, the measurement error was 0.11°±0.02°. Conclusion:The system demonstrates good accuracy and stability, and has potential clinical application value.